CN111303348A - Photocuring waterborne polyurethane emulsion and preparation method and application thereof - Google Patents
Photocuring waterborne polyurethane emulsion and preparation method and application thereof Download PDFInfo
- Publication number
- CN111303348A CN111303348A CN202010074422.9A CN202010074422A CN111303348A CN 111303348 A CN111303348 A CN 111303348A CN 202010074422 A CN202010074422 A CN 202010074422A CN 111303348 A CN111303348 A CN 111303348A
- Authority
- CN
- China
- Prior art keywords
- weight
- parts
- repairing
- monomer
- self
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/006—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polymers provided for in C08G18/00
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/08—Processes
- C08G18/0804—Manufacture of polymers containing ionic or ionogenic groups
- C08G18/0819—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups
- C08G18/0823—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups containing carboxylate salt groups or groups forming them
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/08—Processes
- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
- C08G18/4854—Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
- C08G18/75—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic
- C08G18/751—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring
- C08G18/752—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group
- C08G18/753—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group
- C08G18/755—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
- C08J2375/04—Polyurethanes
- C08J2375/08—Polyurethanes from polyethers
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention provides a photocuring waterborne polyurethane emulsion which is prepared from the following raw materials: 25-35 parts by weight of isophorone diisocyanate; 40-60 parts by weight of polytetrahydrofuran diol; 0.05-0.15 part by weight of dibutyltin dilaurate; 4-6 parts by weight of dimethylolpropionic acid; 3-5 parts by weight of triethylamine; 0.5-2 parts by weight of anhydrous ethylenediamine; 0.5-10 parts by weight of a photo-curing monomer; 3-8 parts of self-repairing monomer; 0.001-0.01 parts by weight of p-hydroxyanisole; water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%; the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine. Compared with the prior art, the photocuring aqueous polyurethane emulsion provided by the invention adopts components with specific content, is polymerized according to molecular structure design, and realizes good interaction, so that a cured film obtained by the photocuring aqueous polyurethane emulsion has excellent mechanical properties and excellent self-repairing properties, and has wide application prospect in the field of flexible sensors.
Description
Technical Field
The invention relates to the technical field of waterborne polyurethane, in particular to a photocuring waterborne polyurethane emulsion and a preparation method and application thereof.
Background
In daily life and industrial applications, prolonging the service life of products is one of the key points of people's attention. However, as the use time increases, the polymer is damaged and destroyed in the use process due to the influence of external conditions such as chemistry, heat, external force and the like, and serious consequences can be caused in the subsequent use, and even the life safety of a user is threatened. The intrinsic self-repairing material does not need an external embedding repairing agent, and can realize self-repairing of the material spontaneously or under certain external stimulation by utilizing reversible dynamic chemical action or supermolecule action in a molecular network. Among them, hydrogen bonding is a supramolecular chemical force widely studied and ubiquitous in natural biomolecules, and structure-specific physiological or biochemical functions such as DNA replication, protein folding, molecular recognition, etc. are all associated with reversible hydrogen bonding. The purpose of the initial research on hydrogen bond polymers is to improve the mechanical properties of materials, but due to the advantages of directionality, reversibility, sensitivity and the like of hydrogen bonds, the hydrogen bond polymers are gradually used for the research of self-repairing materials, and show potential applications in many different fields.
The photocuring waterborne polyurethane is used as a green and environment-friendly polymer material with good comprehensive performance, and the physical and chemical properties of the photocuring waterborne polyurethane can be flexibly adjusted according to requirements, so that the photocuring waterborne polyurethane becomes a focus for developing green and environment-friendly resin at present. Among them, the ultraviolet curing (UV-curing) technology was first proposed in the beginning of the 20 th century, and its "5E" feature (economi, Energy, Efficiency, Environmental friendly and Energy saving) has attracted general attention in recent years to academia and industry. Generally, there are two ways of crosslinking photo-curable aqueous polyurethanes, namely irreversible covalent chemical crosslinking and reversible non-covalent physical crosslinking (hydrogen bonding crosslinking). The chemically crosslinked aqueous polyurethane is mainly a thermosetting polymer and has good mechanical properties such as excellent elasticity, high strength, excellent chemical resistance and the like, but the irreversible chemical crosslinking network limits the application fields, and mainly shows that the properties such as mechanical strength and the like are difficult to restore to the original state after being damaged by the outside, thereby causing difficulty in subsequent repeated application. Because of this, the reversible physical crosslinking modification of the photo-curable waterborne polyurethane by using a reversible non-covalent bond becomes a research hotspot of researchers in the field, and more importantly, the photo-curable waterborne polyurethane can be endowed with a self-repairing performance.
At present, most self-repairing polyurethanes are oleoresin (solvent type polyurethanes), and a large amount of organic solvents are needed in the preparation process of the self-repairing polyurethanes, so that the self-repairing polyurethanes are harmful to human body environment and the like; and the research on environment-friendly waterborne self-repairing polyurethane is very little, and particularly, the hydrogen bond type self-repairing waterborne polyurethane is based on hydrogen bond type self-repairing waterborne polyurethane with excellent mechanical properties and repairing properties. The self-repairing performance of the light-cured waterborne polyurethane is poor because a large number of hydrogen bonds exist in the light-cured waterborne polyurethane, but the hydrogen bonds basically belong to single hydrogen bond action, the acting force is weak, and the self-repairing performance of the light-cured waterborne polyurethane is poor due to the chemical cross-linking structure generated after light curing. Therefore, how to introduce more hydrogen bonds and multiple hydrogen bond actions into the photocuring waterborne polyurethane makes the environment-friendly photocuring waterborne polyurethane have excellent mechanical properties and excellent self-repairing properties, which is a technical problem to be solved by the technical staff in the field.
Disclosure of Invention
In view of the above, the present invention aims to provide a photo-curing aqueous polyurethane emulsion, and a preparation method and an application thereof, and a cured film obtained from the photo-curing aqueous polyurethane emulsion provided by the present invention has excellent mechanical properties and excellent self-repairing properties.
The invention provides a photocuring waterborne polyurethane emulsion which is prepared from the following raw materials:
25-35 parts by weight of isophorone diisocyanate;
40-60 parts by weight of polytetrahydrofuran diol;
0.05-0.15 part by weight of dibutyltin dilaurate;
4-6 parts by weight of dimethylolpropionic acid;
3-5 parts by weight of triethylamine;
0.5-2 parts by weight of anhydrous ethylenediamine;
0.5-10 parts by weight of a photo-curing monomer;
3-8 parts of self-repairing monomer;
0.001-0.01 parts by weight of p-hydroxyanisole;
water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
Preferably, the light-curing monomer is hydroxyethyl methacrylate.
The invention also provides a preparation method of the photocuring waterborne polyurethane emulsion, which comprises the following steps:
a) mixing isophorone diisocyanate and dibutyltin dilaurate, dropwise adding polytetrahydrofuran diol, and carrying out a first reaction to obtain a reaction mixture;
b) adding dimethylolpropionic acid into the reaction mixture obtained in the step a), carrying out a second reaction, sequentially adding triethylamine to salify, adding anhydrous ethylenediamine to carry out chain extension, adding a self-repairing monomer, a light-curing monomer and p-hydroxyanisole, carrying out a third reaction, and finally adding water to emulsify to obtain a light-curing aqueous polyurethane emulsion;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
Preferably, the temperature of the dropwise addition in the step a) is 65-85 ℃ and the time is 10-25 min.
Preferably, the temperature of the first reaction in the step a) is 75-90 ℃ and the time is 1.5-3.5 h.
Preferably, the temperature of the second reaction in the step b) is 65-85 ℃ and the time is 1.5-3.5 h.
Preferably, the temperature of the salifying in the step b) is 40-55 ℃, and the time is 25-65 min;
the chain extension time is 10-35 min.
Preferably, the temperature of the third reaction in the step b) is 55-75 ℃, and the time is 2.5-4.5 h.
Preferably, the step b) further comprises:
adding acetone in the third reaction process to adjust the viscosity of the reaction system; and the acetone is distilled off under reduced pressure after the emulsification process.
The invention also provides a cured film which is prepared by photocuring the photocuring waterborne polyurethane emulsion in the technical scheme.
The invention provides a photocuring waterborne polyurethane emulsion which is prepared from the following raw materials: 25-35 parts by weight of isophorone diisocyanate; 40-60 parts by weight of polytetrahydrofuran diol; 0.05-0.15 part by weight of dibutyltin dilaurate; 4-6 parts by weight of dimethylolpropionic acid; 3-5 parts by weight of triethylamine; 0.5-2 parts by weight of anhydrous ethylenediamine; 0.5-10 parts by weight of a photo-curing monomer; 3-8 parts of self-repairing monomer; 0.001-0.01 parts by weight of p-hydroxyanisole; water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%; the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine. Compared with the prior art, the photocuring aqueous polyurethane emulsion provided by the invention adopts components with specific content, is polymerized according to molecular structure design, and realizes good interaction, so that a cured film obtained by the photocuring aqueous polyurethane emulsion has excellent mechanical properties (flexibility and mechanical toughness) and excellent self-repairing performance, and has wide application prospect in the field of flexible sensors.
In addition, the preparation method provided by the invention has the advantages of simple process and mild conditions, can realize cost optimization by adjusting the specific dosage of the formula, and has great application potential.
Drawings
FIG. 1 shows FT-IR spectra before and after curing of a photo-curable aqueous polyurethane emulsion provided in example 2 of the present invention;
FIG. 2 shows the self-repairing effect of scratches of a cured film prepared from the photo-curable aqueous polyurethane emulsion provided in embodiments 1 to 4 of the present invention;
FIG. 3 is a curve showing the change of the repair efficiency of tensile strength and elongation at break of the cured film prepared from the photo-cured aqueous polyurethane emulsion provided in embodiments 1 to 4 of the present invention under different repair conditions.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a photocuring waterborne polyurethane emulsion which is prepared from the following raw materials:
25-35 parts by weight of isophorone diisocyanate;
40-60 parts by weight of polytetrahydrofuran diol;
0.05-0.15 part by weight of dibutyltin dilaurate;
4-6 parts by weight of dimethylolpropionic acid;
3-5 parts by weight of triethylamine;
0.5-2 parts by weight of anhydrous ethylenediamine;
0.5-10 parts by weight of a photo-curing monomer;
3-8 parts of self-repairing monomer;
0.001-0.01 parts by weight of p-hydroxyanisole;
water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
The sources of the isophorone diisocyanate (IPDI), polytetrahydrofuran glycol (PTMG-1000), dibutyltin dilaurate (DBDTL), dimethylolpropionic acid (DMPA), Triethylamine (TEA), anhydrous Ethylenediamine (EDA) and p-hydroxyanisole (MEHQ) are not particularly limited, and commercially available products well known to those skilled in the art can be used.
In the invention, the photocuring aqueous polyurethane emulsion comprises 25-35 parts by weight of isophorone diisocyanate, preferably 30 parts by weight; the light-cured waterborne polyurethane emulsion comprises 40-60 parts by weight of polytetrahydrofuran glycol, preferably 45 parts by weight; the photocuring waterborne polyurethane emulsion comprises 0.05-0.15 part by weight of dibutyltin dilaurate, preferably 0.08 part by weight; the light-cured waterborne polyurethane emulsion comprises 4-6 parts by weight of dimethylolpropionic acid, preferably 5.5 parts by weight; the light-cured waterborne polyurethane emulsion comprises 3-5 parts by weight of triethylamine, preferably 4.15 parts by weight; the light-cured waterborne polyurethane emulsion comprises 0.5-2 parts by weight of anhydrous ethylenediamine, preferably 0.78 part by weight; the light-cured water-based polyurethane emulsion comprises 0.001-0.01 weight part of p-hydroxyanisole, preferably 0.001-0.004 weight part, and more preferably 0.003 weight part.
In the present invention, the photo-curable monomer is preferably hydroxyethyl methacrylate (HEMA); the structural formula is as follows:
the source of the photocurable monomer is not particularly limited in the present invention, and a commercially available product of the above hydroxyethyl methacrylate known to those skilled in the art may be used. In the invention, the light-cured water-based polyurethane emulsion comprises 0.5-10 parts by weight of light-cured monomer, preferably 0.65-2.6 parts by weight.
In the invention, the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine (UPy); the structural formula is as follows:
the source of the self-repairing monomer is not particularly limited in the invention, and the commercially available product of the multiple hydrogen bond monomer 2-amino-4-hydroxy-6-methylpyrimidine known to the person skilled in the art can be adopted.
The invention adopts the ureido pyrimidinone (2-amino-4-hydroxy-6-methylpyrimidine) which is a monomer capable of forming a stable dimer through self-assembly of quadruple hydrogen bond acting force, can generate larger binding energy and stability when quadruple hydrogen bond crosslinking acts, and can reversibly break and bond under the stimulation of external factors such as temperature, pH value, pressure and the like; the invention utilizes reversible quadruple hydrogen bonds and high dimer constants of 2-amino-4-hydroxy-6-methylpyrimidine to prepare the self-repairable aqueous photo-curable polyurethane with high strength and high toughness.
In the invention, the photo-curing aqueous polyurethane emulsion comprises 3-8 parts by weight of self-repairing monomer, preferably 3.75-5.63 parts by weight.
In the present invention, the water may be deionized water well known to those skilled in the art; the amount of water is such that the emulsion has a solids content of 25 wt.% to 35 wt.%, preferably such that the emulsion has a solids content of 30 wt.%.
Generally, materials with excellent self-repairing performance have poor mechanical properties, so that the development of self-repairing polyurethane with both repairing performance and mechanical properties is a major challenge today. The photocuring aqueous polyurethane emulsion provided by the invention adopts components with specific content, is polymerized according to molecular structure design, and realizes good interaction, so that a cured film obtained by the photocuring aqueous polyurethane emulsion has excellent mechanical properties (flexibility and mechanical toughness) and excellent self-repairing performance, and has wide application prospect in the field of flexible sensors. Compared with oil-based polyurethane, the invention inspires the traditional emulsion polymerization, and the nano-aqueous polyurethane emulsion obtained by emulsification shows wide application due to the nano size, and in principle, nano emulsion particles with controllable size can be prepared by emulsification; these supramolecular polymer-based nanomaterials, as a coupling of covalent and non-covalent bonds, can exhibit various unique properties, such as well-defined composition, high stability and susceptibility to degradation; they may have great potential for applications in many fields, such as controlled release, nanoreactors, sensing and imaging.
The invention selects the interaction of quadruple hydrogen bonds as the main driving force for self-repairing light-cured waterborne polyurethane, takes dimethylolpropionic acid (DMPA) as a hydrophilic monomer, 2-amino-4-hydroxy-6-methylpyrimidine (UPy) as a quadruple hydrogen bond monomer and hydroxyethyl methacrylate (HEMA) as a light-cured monomer, combines the UV curing technology and the self-repairing concept, and develops the waterborne polyurethane emulsion which has the components of self-repairing light curing and no additional surfactant. The retrieval result shows that the self-repairing photocuring waterborne polyurethane with the polyurethane as the main chain, the UPy unit modified at the tail end and the photocuring unit is not reported; besides the four-fold hydrogen bond acting force formed by the UPy dimer in a close arrangement, the simple hydrogen bond formed by the urethane, carbamido and other units formed by the polyurethane also increases the hydrogen bond density in the system; the hydrogen bonding of the multilevel structure is more helpful to the formation of self-repairing polyurethane under the mutual cooperation. In addition, in the preferred embodiment of the invention, the low HEMA content endows the system with a relatively loose chemical cross-linked network structure, which can provide an elastic large frame, maintain the elasticity of the cured film, enable the cured film to quickly recover to the original shape after being stretched, and is helpful for promoting the effective and quick rearrangement of hydrogen bonds after being broken, so that the recovery capability of the material is enhanced; meanwhile, a physical crosslinking network can be constructed by hydrogen bonds formed by polar groups such as urethane groups and urea groups in the UPy monomer and polyurethane, and a self-repairing photocuring waterborne polyurethane with high strength and high toughness is constructed through the synergistic effect between a chemical crosslinking network formed by double bond curing and the physical crosslinking network formed by the action of the hydrogen bonds.
The invention also provides a preparation method of the photocuring waterborne polyurethane emulsion, which comprises the following steps:
a) mixing isophorone diisocyanate and dibutyltin dilaurate, dropwise adding polytetrahydrofuran diol, and carrying out a first reaction to obtain a reaction mixture;
b) adding dimethylolpropionic acid into the reaction mixture obtained in the step a), carrying out a second reaction, sequentially adding triethylamine to salify, adding anhydrous ethylenediamine to carry out chain extension, adding a self-repairing monomer, a light-curing monomer and p-hydroxyanisole, carrying out a third reaction, and finally adding water to emulsify to obtain a light-curing aqueous polyurethane emulsion;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
In the present invention, the preparation method is preferably performed under the protection of nitrogen; as the apparatus for the preparation method, a four-necked flask equipped with a stirring blade, a thermometer and a condenser, which is well known to those skilled in the art, is used, and the present invention is not particularly limited thereto.
According to the invention, firstly, isophorone diisocyanate and dibutyltin dilaurate are mixed, polytetrahydrofuran diol is dripped, and then a first reaction is carried out to obtain a reaction mixture. In the present invention, the isophorone diisocyanate, dibutyltin dilaurate and polytetrahydrofuran diol are the same as those in the above technical solution, and are not described herein again.
In the invention, the dripping temperature is preferably 65-85 ℃, and more preferably 70-80 ℃; the dropping time is preferably 10 to 25min, more preferably 15 to 20 min.
After the dropwise adding is finished, continuously heating to carry out a first reaction; the temperature of the first reaction is preferably 75-90 ℃, and more preferably 80-85 ℃; the time for the first reaction is preferably 1.5 to 3.5 hours, and more preferably 2 to 3 hours.
After the reaction mixture is obtained, dimethylolpropionic acid is added into the obtained reaction mixture to carry out a second reaction, triethylamine is sequentially added to carry out salification, anhydrous ethylenediamine is added to carry out chain extension, a self-repairing monomer, a photo-curing monomer and p-hydroxyanisole are added to carry out a third reaction, and finally water is added to carry out emulsification, so that the photo-curing waterborne polyurethane emulsion is obtained. The dimethylolpropionic acid, the triethylamine, the anhydrous ethylenediamine, the self-repairing monomer, the photo-curing monomer and the p-hydroxyanisole are the same as those in the technical scheme, and are not described again.
The present invention preferably further comprises:
the resulting reaction mixture was cooled to below 55 ℃ and dimethylolpropionic acid was added.
In the invention, the temperature of the second reaction is preferably 65-85 ℃, and more preferably 70-80 ℃; the time of the second reaction is preferably 1.5 to 3.5 hours, and more preferably 2 to 3 hours.
In the invention, the temperature of the salification is preferably 40-55 ℃, and more preferably 45-50 ℃; the time for salifying is preferably 25min to 65min, and more preferably 30min to 60 min. In the invention, the time of chain extension is preferably 10min to 35min, and more preferably 15min to 30 min; the process of chain extension continues at the temperature of the previous salt formation.
In the invention, the temperature of the third reaction is preferably 55-75 ℃, and more preferably 60-70 ℃; the time of the third reaction is preferably 2.5 to 4.5 hours, and more preferably 3 to 4 hours. In the present invention, the progress of the third reaction is preferably followed by titration with toluene-di-n-butylamine.
In the present invention, the step b) preferably further comprises:
adding acetone in the third reaction process to adjust the viscosity of the reaction system; and the acetone is distilled off under reduced pressure after the emulsification process.
In the present invention, the amount of the added water is an amount to make the solid content of the emulsion be 25 wt.% to 35 wt.%, preferably an amount to make the solid content of the emulsion be 30 wt.%.
In the present invention, the emulsification is preferably performed by high-speed stirring, so as to disperse the emulsion uniformly; the time for emulsification is preferably 0.5 to 2.5 hours, more preferably 1 to 2 hours.
The preparation method provided by the invention has the advantages of simple process and mild conditions, can realize cost optimization by adjusting the specific dosage of the formula, and has great application potential.
The invention also provides a cured film which is prepared by photocuring the photocuring waterborne polyurethane emulsion in the technical scheme. In the invention, the preparation process of the cured film specifically comprises the following steps:
adding a photoinitiator into the photocuring waterborne polyurethane emulsion, ultrasonically oscillating for 25-35 min to uniformly dissolve the photoinitiator in the emulsion, pouring the emulsion containing the photoinitiator into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in a 75-85 ℃ forced air drying oven for drying for 22-26 h, and after water in a coating film is slowly evaporated, performing photocuring for 4-6 min in an ultraviolet photocuring machine to obtain a cured film;
more preferably:
adding a photoinitiator into the photocuring waterborne polyurethane emulsion, performing ultrasonic oscillation for 30min to uniformly dissolve the photoinitiator in the emulsion, pouring the emulsion containing the photoinitiator into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in an air-blowing drying oven at 80 ℃ for drying for 24h, and performing photocuring on the emulsion in an ultraviolet curing machine for 5min after water in a coating film is slowly evaporated to obtain a cured film.
The present invention is not particularly limited with respect to the specific kind and source of the photoinitiator, and commercially available photoinitiators for UV curing known to those skilled in the art may be used.
In the invention, the light curing process preferably adopts a UV curing mode, and compared with the traditional technical scheme that the heat curing needs to be carried out at high temperature (>120 ℃), the UV curing is an environment-friendly, energy-saving and efficient green curing technology, the defect that some heat-sensitive substrates are easy to damage under the high-temperature heat curing is avoided, and the resin is favorably cured and molded under mild conditions; and the relatively loose chemical crosslinking network structure formed by UV curing can provide an elastic large frame, so that the elasticity of the curing film is maintained, the curing film can be quickly restored to the original shape after being stretched, effective and quick rearrangement of hydrogen bonds after breakage is facilitated, and the restoring capability of the material is enhanced.
Compared with solvent type polyurethane, the self-repairable photo-curable waterborne polyurethane prepared by the invention replaces organic solvent with water, is an environment-friendly resin, has better biocompatibility, and can be used for surface coating of medical instruments or articles, human skin and the like. Meanwhile, the nano waterborne polyurethane emulsion obtained by emulsification shows wide application due to the nano size; in principle, it is possible to prepare nanoemulsion particles with controlled size by emulsification; the supermolecule polymer-based nano material can show various unique properties such as definite components, high stability and easy degradation as the coupling of covalent bonds and non-covalent bonds; they may have great potential for applications in many fields, such as controlled release, nanoreactors, sensing and imaging.
In addition, in the preferred embodiment of the invention, the double bond-containing monomer hydroxyethyl methacrylate (HEMA) and the quadruple hydrogen bond monomer 2-amino-4-hydroxy-6-methylpyrimidine (UPy) are adopted, and the synergistic effect of the two is exerted to the maximum extent by adjusting the proportion of the two, so that the self-repairing light-cured waterborne polyurethane is prepared; the HEMA can provide an elastic large frame through a relatively loose chemical crosslinking network structure formed by UV curing, so that the elasticity of the cured film is maintained, the cured film can be quickly restored to the original shape after being stretched, effective and quick rearrangement of hydrogen bonds after breakage is facilitated, and the self-repairing capability of the material is enhanced; on the other hand, the UPy monomer and polar groups such as carbamate and carbamide in polyurethane form hydrogen bonds to construct a physical crosslinking network, the density of the hydrogen bonds in the system is improved along with the increase of the UPy monomer, and the hydrogen bonds are more easily broken and rearranged, so that the curing film can be more efficiently subjected to self-repairing behavior when being damaged by the outside; therefore, a self-repairing photocuring waterborne polyurethane with high strength and high toughness is constructed through the synergistic effect between a chemical crosslinking network formed by double bond curing and a physical crosslinking network formed by hydrogen bond action; the good stretchability and flexibility of the resin make the resin have the potential of being applied to flexible sensors by combining the properties of the resin.
The invention provides a photocuring waterborne polyurethane emulsion which is prepared from the following raw materials: 25-35 parts by weight of isophorone diisocyanate; 40-60 parts by weight of polytetrahydrofuran diol; 0.05-0.15 part by weight of dibutyltin dilaurate; 4-6 parts by weight of dimethylolpropionic acid; 3-5 parts by weight of triethylamine; 0.5-2 parts by weight of anhydrous ethylenediamine; 0.5-10 parts by weight of a photo-curing monomer; 3-8 parts of self-repairing monomer; 0.001-0.01 parts by weight of p-hydroxyanisole; water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%; the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine. Compared with the prior art, the photocuring aqueous polyurethane emulsion provided by the invention adopts components with specific content, is polymerized according to molecular structure design, and realizes good interaction, so that a cured film obtained by the photocuring aqueous polyurethane emulsion has excellent mechanical properties (flexibility and mechanical toughness) and excellent self-repairing performance, and has wide application prospect in the field of flexible sensors.
In addition, the preparation method provided by the invention has the advantages of simple process and mild conditions, can realize cost optimization by adjusting the specific dosage of the formula, and has great application potential.
To further illustrate the present invention, the following examples are provided for illustration. The starting materials used in the following examples of the present invention are all commercially available products.
Example 1
(1) The raw material ratio is as follows:
30g of isophorone diisocyanate (IPDI);
polytetrahydrofuran diol (PTMG-1000)45 g;
0.08g of dibutyltin dilaurate (DBDTL);
5.5g dimethylolpropionic acid (DMPA);
4.15g of Triethylamine (TEA);
0.78g of anhydrous Ethylenediamine (EDA);
2.60g of hydroxyethyl methacrylate (HEMA);
3.75g of 2-amino-4-hydroxy-6-methylpyrimidine (UPy);
p-hydroxyanisole (MEHQ, added in an amount of 0.15 wt.% of HEMA monomer) 0.004 g;
proper amount of acetone;
deionized water was metered in at a solids content of 30% of the emulsion.
(2) The preparation method comprises the following steps:
under the protection of nitrogen, adding 30g of IPDI and 0.08g of DBDTL into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, heating to 70-80 ℃, and dropwise adding 45g of PTMG-1000 for 15-20 min; after the dropwise adding is finished, continuously heating to 80-85 ℃ and reacting for 2-3 h; then cooling to 40-50 ℃, adding 5.5g of DMPA, then heating to 70-80 ℃ again, and reacting for 2-3 h; then cooling to 45-50 ℃, adding 4.15g of TEA to react for 30-60 min for salification; then adding 0.78g of EDA to carry out chain extension for 15min to 30 min; after chain expanding, adding 3.75g UPy, 2.60g HEMA and 0.004g MEHQ, heating to 60-70 ℃, reacting for 3-4 h, and adding a proper amount of acetone to reduce viscosity in the reaction process; in the process, the reaction process is tracked by a toluene-di-n-butylamine titration method, finally, a certain amount of deionized water is added to control the solid content of the system to be 30%, the mixture is stirred at a high speed for 1 to 2 hours for emulsification, and acetone is evaporated out under reduced pressure after the emulsion is uniformly dispersed, so that the photocuring waterborne polyurethane emulsion is obtained.
Example 2
(1) The raw material ratio is as follows:
30g of isophorone diisocyanate (IPDI);
polytetrahydrofuran diol (PTMG-1000)45 g;
0.08g of dibutyltin dilaurate (DBDTL);
5.5g dimethylolpropionic acid (DMPA);
4.15g of Triethylamine (TEA);
0.78g of anhydrous Ethylenediamine (EDA);
hydroxyethyl methacrylate (HEMA)1.95 g;
4.38g of 2-amino-4-hydroxy-6-methylpyrimidine (UPy);
p-hydroxyanisole (MEHQ, added in an amount of 0.15 wt.% of HEMA monomer) 0.003 g;
proper amount of acetone;
deionized water was metered in at a solids content of 30% of the emulsion.
(2) The preparation method comprises the following steps:
under the protection of nitrogen, adding 30g of IPDI and 0.08g of DBDTL into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, heating to 70-80 ℃, and dropwise adding 45g of PTMG-1000 for 15-20 min; after the dropwise adding is finished, continuously heating to 80-85 ℃ and reacting for 2-3 h; then cooling to 40-50 ℃, adding 5.5g of DMPA, then heating to 70-80 ℃ again, and reacting for 2-3 h; then cooling to 45-50 ℃, adding 4.15g of TEA to react for 30-60 min for salification; then adding 0.78g of EDA to carry out chain extension for 15min to 30 min; after chain expanding, adding 4.38g of UPy, 1.95g of HEMA and 0.003g of MEHQ, heating to 60-70 ℃, reacting for 3-4 h, and adding a proper amount of acetone to adjust the viscosity of the reaction system; in the process, the reaction process is tracked by a toluene-di-n-butylamine titration method, finally, a certain amount of deionized water is added to control the solid content of the system to be 30%, the mixture is stirred at a high speed for 1 to 2 hours for emulsification, and acetone is evaporated out under reduced pressure after the emulsion is uniformly dispersed, so that the photocuring waterborne polyurethane emulsion is obtained.
Example 3
(1) The raw material ratio is as follows:
30g of isophorone diisocyanate (IPDI);
polytetrahydrofuran diol (PTMG-1000)45 g;
0.08g of dibutyltin dilaurate (DBDTL);
5.5g dimethylolpropionic acid (DMPA);
4.15g of Triethylamine (TEA);
0.78g of anhydrous Ethylenediamine (EDA);
1.30g of hydroxyethyl methacrylate (HEMA);
5.01g of 2-amino-4-hydroxy-6-methylpyrimidine (UPy);
p-hydroxyanisole (MEHQ, added in an amount of 0.15 wt.% of HEMA monomer) 0.002 g;
proper amount of acetone;
deionized water was metered in at a solids content of 30% of the emulsion.
(2) The preparation method comprises the following steps:
under the protection of nitrogen, adding 30g of IPDI and 0.08g of DBDTL into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, heating to 70-80 ℃, and dropwise adding 45g of PTMG-1000 for 15-20 min; after the dropwise adding is finished, continuously heating to 80-85 ℃ and reacting for 2-3 h; then cooling to 40-50 ℃, adding 5.5g of DMPA, then heating to 70-80 ℃ again, and reacting for 2-3 h; then cooling to 45-50 ℃, adding 4.15g of TEA to react for 30-60 min for salification; then adding 0.78g of EDA to carry out chain extension for 15min to 30 min; after chain expansion, adding 5.01g of UPy, 1.30g of HEMA and 0.002g of MEHQ, heating to 60-70 ℃, reacting for 3-4 h, and adding a proper amount of acetone to adjust the viscosity of the reaction system; in the process, the reaction process is tracked by a toluene-di-n-butylamine titration method, finally, a certain amount of deionized water is added to control the solid content of the system to be 30%, the mixture is stirred at a high speed for 1 to 2 hours for emulsification, and acetone is evaporated out under reduced pressure after the emulsion is uniformly dispersed, so that the photocuring waterborne polyurethane emulsion is obtained.
Example 4
(1) The raw material ratio is as follows:
30g of isophorone diisocyanate (IPDI);
polytetrahydrofuran diol (PTMG-1000)45 g;
0.08g of dibutyltin dilaurate (DBDTL);
5.5g dimethylolpropionic acid (DMPA);
4.15g of Triethylamine (TEA);
0.78g of anhydrous Ethylenediamine (EDA);
0.65g of hydroxyethyl methacrylate (HEMA);
5.63g of 2-amino-4-hydroxy-6-methylpyrimidine (UPy);
p-hydroxyanisole (MEHQ, added in an amount of 0.15 wt.% of HEMA monomer) 0.001 g;
proper amount of acetone;
deionized water was metered in at a solids content of 30% of the emulsion.
(2) The preparation method comprises the following steps:
under the protection of nitrogen, adding 30g of IPDI and 0.08g of DBDTL into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, heating to 70-80 ℃, and dropwise adding 45g of PTMG-1000 for 15-20 min; after the dropwise adding is finished, continuously heating to 80-85 ℃ and reacting for 2-3 h; then cooling to 40-50 ℃, adding 5.5g of DMPA, then heating to 70-80 ℃ again, and reacting for 2-3 h; then cooling to 45-50 ℃, adding 4.15g of TEA to react for 30-60 min for salification; then adding 0.78g of EDA to carry out chain extension for 15min to 30 min; after chain expanding, adding 5.63g UPy, 0.65g HEMA and 0.001g MEHQ, heating to 60-70 ℃, reacting for 3-4 h, and adding a proper amount of acetone to adjust the viscosity of the reaction system; in the process, the reaction process is tracked by a toluene-di-n-butylamine titration method, finally, a certain amount of deionized water is added to control the solid content of the system to be 30%, the mixture is stirred at a high speed for 1 to 2 hours for emulsification, and acetone is evaporated out under reduced pressure after the emulsion is uniformly dispersed, so that the photocuring waterborne polyurethane emulsion is obtained.
Comparative example 1
(1) The raw material ratio is as follows:
30g of isophorone diisocyanate (IPDI);
polytetrahydrofuran diol (PTMG-1000)45 g;
0.08g of dibutyltin dilaurate (DBDTL);
5.5g dimethylolpropionic acid (DMPA);
4.15g of Triethylamine (TEA);
0.78g of anhydrous Ethylenediamine (EDA);
6.51g of hydroxyethyl methacrylate (HEMA);
p-hydroxyanisole (MEHQ, added in an amount of 0.15 wt.% of HEMA monomer) 0.01 g;
proper amount of acetone;
deionized water was metered in at a solids content of 30% of the emulsion.
(2) The preparation method comprises the following steps:
under the protection of nitrogen, adding 30g of IPDI and 0.08g of DBDTL into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, heating to 70-80 ℃, and dropwise adding 45g of PTMG-1000 for 15-20 min; after the dropwise adding is finished, continuously heating to 80-85 ℃ and reacting for 2-3 h; then cooling to 40-50 ℃, adding 5.5g of DMPA, then heating to 70-80 ℃ again, and reacting for 2-3 h; then cooling to 45-50 ℃, adding 4.15g of TEA to react for 30-60 min for salification; then adding 0.78g of EDA to carry out chain extension for 15min to 30 min; after chain expanding, adding 6.51g of HEMA and 0.01g of MEHQ, heating to 60-70 ℃, reacting for 3-4 h, and adding a proper amount of acetone to adjust the viscosity of the reaction system; in the process, the reaction process is tracked by a toluene-di-n-butylamine titration method, finally, a certain amount of deionized water is added to control the solid content of the system to be 30%, the mixture is stirred at a high speed for 1 to 2 hours for emulsification, and acetone is evaporated out under reduced pressure after the emulsion is uniformly dispersed, so that the photocuring waterborne polyurethane emulsion is obtained.
The application example is as follows:
respectively adding a photoinitiator Darocur1173, 3 wt% (based on the content of resin) into the photocuring waterborne polyurethane emulsion provided in the embodiments 1-4 and the comparative example 1, performing ultrasonic oscillation for 30min to uniformly dissolve the photoinitiator in the emulsion, pouring the emulsion containing the photoinitiator into a polytetrafluoroethylene mold, placing the polytetrafluoroethylene mold in an air-blowing drying oven at 80 ℃ for drying for 24h, and performing photocuring on the emulsion for 5min in an ultraviolet curing machine (RX300-1, Dongguan Cui Co., Ltd.) after water in a coating film is slowly evaporated to prepare a corresponding cured film.
And (3) performance testing:
(1) and (3) particle size analysis: the emulsion was diluted to 1 vol.% with deionized water, and the particle size and distribution thereof were measured with a Zeta-type nanosize analyzer from beckmann coulter, usa, after ultrasonic oscillation, with a number of scans of 70.
(2) Mechanical stability of the emulsion: taking a proper amount of the emulsion in a centrifugal test tube, centrifuging for 30min at 3000r/min by using a centrifuge TG1650-WS of Shanghai Luxiang apparatus company, taking out the centrifugal tube, standing vertically at room temperature for 48h, and observing the state of the emulsion.
(3) Infrared spectrum analysis: the test was carried out by using a Magna360 type Fourier transform infrared spectrometer manufactured by Nicolet corporation, USA, and characterizing a cured film by ATR method at 4000cm-1～600cm-1The sample is detected in the wave number range of (2), the scanning times are 32, and the wave number resolution is 4cm-1。
(4) And (3) analyzing the performance of the coating:
① flexibility is tested according to GB/T1731-93 standard, the flexibility of the cured film is characterized by bending test, the film coated on the tinplate is folded in half by taking steel rods with different diameters as axes, and the flexibility of the paint film is expressed by the diameter of the smallest axis rod which does not cause the damage of the paint film.
② Shore hardness is measured according to GB/T6031-1998 standard by using an LX-A Shore hardness meter, and three points are selected for measurement and then an average value is taken.
③ gel fraction was measured according to ASTM D2765-84, and the weight loss was calculated by soaking the cured film in chloroform for 24 hours at room temperature.
(5) Determination of self-repairing Properties: (1) after scratching a cured film with the thickness of 0.5mm by a blade to a depth of about 0.2mm, putting the cured film with the scratch in a blast drying oven at a test temperature for heating and repairing; observing the repairing degree of the cured film before and after the scratch by a polarizing microscope (BKPOL, Chongqing, China); (2) and (3) cured film tensile property repair analysis: cutting a dumbbell-shaped cured film sample into two halves by a blade, then placing two fracture sections of the cured film in close contact with each other at a test temperature (under the pressure of 0.2 MPa) for 24h self-repairing, taking out the cured film, cooling and then carrying out a tensile test, wherein the tensile rate is 50mm/min, and the average value of the tensile property of each sample is taken as the standard. Finally, calculating the repairing Efficiency (HE%) of the sample according to the formula (1-1);
in the formula, deltarepairedDenotes the tensile strength or elongation at break, delta, of the repaired specimenoriginThe tensile strength or elongation at break of the original specimen is shown.
And (3) testing results:
(1) the results of the analysis of the properties of the emulsions and latex films are shown in Table 1;
TABLE 1 analysis of emulsion and latex film Properties
From table 1, it can be seen that the content of the quadruple hydrogen bond monomer UPy and the photo-cured acrylate monomer HEMA has little influence on the performance of the emulsion, and the emulsion has good stability and small particle size; this indicates that UPy and HEMA polymerize well onto the polymer.
When the content of HEMA is gradually increased, the Shore hardness and the gel fraction of the latex film are gradually increased, and the flexibility is basically unchanged. This is because the higher double bond content results in a coating with a higher crosslink density, which in turn has a critical effect on the improvement of the hardness of the coating; meanwhile, the gel fraction is also related to the crosslinking density, and from example 4 to example 1, the gel fraction is improved from 16.30 percent to 70.81 percent due to the increase of double bonds; when the HEMA content is the highest (comparative example 1), the gel rate of the latex film is 85.43 percent.
In addition, the flexibility of a coating is a characteristic of the coating's ability to accommodate the deforming motion of its support, sometimes referred to as "elasticity" or "ductility"; the flexibility of the coating is mainly determined by the flexibility of the resin, when all the coatings are folded in half, the coating at the folded position can be found not to crack or break, which indicates that the coating has good flexibility; this is because the soft segment of the polyurethane is PTMG-1000 with ether bond (C-O-C), the molecular chain structure is regular, and the flexibility is excellent, and the flexibility of the resin can be improved obviously.
(2) Infrared analysis of the cured film is shown in fig. 1; FIG. 1 is FT-IR spectra before and after curing of a photo-curable aqueous polyurethane emulsion provided in example 2 of the present invention, wherein (a) is before curing and (b) is after curing; the sample is 3320cm before and after UV light curing-1All appear with infrared characteristic peak of carbamate (-NHCO), and at 2270cm-1No infrared characteristic peak of-NCO appears; the samples were at 1660cm before UV light irradiation-1(C: C stretching vibration) 810cm-1(the out-of-plane bending vibration of C-H) shows absorption peaks, which indicates that HEMA is successfully polymerized on the polyurethane structure; but 1660cm after UV light irradiation-1、810cm-1The double bond characteristic peak disappears, which indicates that the sample is successfully UV-cured, namely FT-IR spectrogram further indicates the successful synthesis of the self-repairing light-cured waterborne polyurethane.
(3) Self-repairing performance analysis of the cured film:
the self-repairing performance of the cured film can be observed by an optical microscope to observe the repairing degree of the scratch, and the result is shown in FIG. 2; FIG. 2 shows the self-repairing effect of scratches on a cured film prepared from the photo-curable aqueous polyurethane emulsion provided in examples 1 to 4 of the present invention, wherein (a) is example 1, (b) is example 2, (c) is example 3, and (d) is example 4. The observation result shows that the change of the proportion of UPy and HEMA and the temperature have important influence on the self-repairing performance of the sample; when the temperature is 80 ℃, the scratch depths of the examples 1 and 2 are slightly reduced after 24h repair, but obvious defects can still be observed, and the scratch of the example 3 is basically healed; after the temperature is increased to 100 ℃, after 90min of repair, the scratches of the example 1 are slightly closed, the depths of the scratches are reduced, but obvious marks exist on the surface of the cured film, the scratches of the example 2 are basically closed, but fine marks exist on the surface of the cured film, and the example 3 is completely healed; after further heating to 120 ℃ and 15min of repair, the samples of example 1 were still clearly scratched, while almost no scratches were observed in the remaining three samples.
The result shows that the content of UPy is beneficial to improving the self-repairing efficiency of the sample strip, and excessive HEMA can cause the material to lose the repairing performance, improve the temperature, reduce the repairing time of the sample strip and be beneficial to improving the self-repairing efficiency; this is because the cured film is self-healing by mobility of the polymer chains throughout the cleaved surface and disruption and reestablishment of multiple hydrogen bonding networks; with the relative reduction of the content of HEMA, the chemical crosslinking density in the cured film is reduced, molecular chains move more easily, and the density of quadruple hydrogen bonds is increased by UPy dimers with relatively high concentration, so that the cured film has better self-healing performance; it can be seen that the reversibility of hydrogen bonds is the key of the whole self-healing process of the self-repairing photocuring waterborne polyurethane curing film.
Fig. 3 is a change curve of the tensile strength and the elongation at break repair efficiency of the cured film prepared from the photo-cured aqueous polyurethane emulsion provided in embodiments 1 to 4 of the present invention under different repair conditions, wherein fig. 3a and 3b are respectively the stress and strain repair efficiency of the cured film at different temperatures (24 h). The result shows that the tensile strength-elongation at break efficiency of the cured film is obviously improved along with the rise of the temperature, which indicates that the mechanical tensile property of the cured film is effectively recovered; the reason is that the increase of the temperature can promote the dissociation of hydrogen bonds, the molecular chain segment has better mobility and can move at the section through the diffusion of the molecular chain, and the dynamic hydrogen bonds at the section promote the reformation of a new physical cross-linked network through dissociation-rearrangement, so the tensile mechanical repair performance of the sample strip is greatly improved.
FIGS. 3c and 3d are graphs showing the tensile strength and elongation at break healing efficiency of the cured films at different healing times (100 ℃ C.), respectively. The result shows that the tensile mechanical property repair efficiency of the sample is remarkably improved along with the increase of the repair time; this is because the effective contact time of hydrogen bonds at the fracture increases due to the increase of the repair time, UPy dimers and other hydrogen bonds in the polymer network can form multistage reversible hydrogen bonds through hydrogen donor-acceptor interactions; along with the extension of the repair time, the rearrangement and connection of the hydrogen bonds are tighter and firmer, and the method has important influence on the rearrangement of the hydrogen bonds to form a compact physical network, thereby improving the self-repair capability of the sample. It is noted that the tensile strength of the example 4 sample increased after the repair time increased to 36 hours, with the repair efficiencies of 119.84% and 192.39% for tensile strengths at 36 and 48 hours; under the condition of low density of the chemical crosslinking network, the long-time high-temperature state can promote the initiation free radical embedded in the molecular chain segment to be newly exposed, and initiate the post-curing of the residual double bonds in the sample strip to obtain a more compact chemical crosslinking network, so that the tensile strength of the sample is improved.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The photocuring waterborne polyurethane emulsion is prepared from the following raw materials:
25-35 parts by weight of isophorone diisocyanate;
40-60 parts by weight of polytetrahydrofuran diol;
0.05-0.15 part by weight of dibutyltin dilaurate;
4-6 parts by weight of dimethylolpropionic acid;
3-5 parts by weight of triethylamine;
0.5-2 parts by weight of anhydrous ethylenediamine;
0.5-10 parts by weight of a photo-curing monomer;
3-8 parts of self-repairing monomer;
0.001-0.01 parts by weight of p-hydroxyanisole;
water, wherein the water is used in an amount which enables the solid content of the emulsion to be 25 wt.% to 35 wt.%;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
2. The photocurable aqueous polyurethane emulsion according to claim 1, wherein the photocurable monomer is hydroxyethyl methacrylate.
3. A method for preparing the photo-curable aqueous polyurethane emulsion according to any one of claims 1 to 2, comprising the steps of:
a) mixing isophorone diisocyanate and dibutyltin dilaurate, dropwise adding polytetrahydrofuran diol, and carrying out a first reaction to obtain a reaction mixture;
b) adding dimethylolpropionic acid into the reaction mixture obtained in the step a), carrying out a second reaction, sequentially adding triethylamine to salify, adding anhydrous ethylenediamine to carry out chain extension, adding a self-repairing monomer, a light-curing monomer and p-hydroxyanisole, carrying out a third reaction, and finally adding water to emulsify to obtain a light-curing aqueous polyurethane emulsion;
the self-repairing monomer is 2-amino-4-hydroxy-6-methylpyrimidine.
4. The preparation method according to claim 3, wherein the temperature of the dropwise addition in the step a) is 65-85 ℃ and the time is 10-25 min.
5. The preparation method according to claim 3, wherein the temperature of the first reaction in the step a) is 75-90 ℃ and the time is 1.5-3.5 h.
6. The preparation method according to claim 3, wherein the temperature of the second reaction in step b) is 65-85 ℃ and the time is 1.5-3.5 h.
7. The preparation method according to claim 3, wherein the temperature for salification in step b) is 40-55 ℃ and the time is 25-65 min;
the chain extension time is 10-35 min.
8. The preparation method according to claim 3, wherein the temperature of the third reaction in the step b) is 55-75 ℃ and the time is 2.5-4.5 h.
9. The method according to any one of claims 3 to 8, wherein the step b) further comprises:
adding acetone in the third reaction process to adjust the viscosity of the reaction system; and the acetone is distilled off under reduced pressure after the emulsification process.
10. A cured film obtained by photocuring the photocurable aqueous polyurethane emulsion according to any one of claims 1 to 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010074422.9A CN111303348A (en) | 2020-01-22 | 2020-01-22 | Photocuring waterborne polyurethane emulsion and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010074422.9A CN111303348A (en) | 2020-01-22 | 2020-01-22 | Photocuring waterborne polyurethane emulsion and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111303348A true CN111303348A (en) | 2020-06-19 |
Family
ID=71148970
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010074422.9A Pending CN111303348A (en) | 2020-01-22 | 2020-01-22 | Photocuring waterborne polyurethane emulsion and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111303348A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112480350A (en) * | 2020-11-06 | 2021-03-12 | 中国科学院化学研究所 | Hydrophilic polyurethane, preparation method thereof, biological printing composite material and application |
| CN113817119A (en) * | 2021-09-28 | 2021-12-21 | 长春工业大学 | Preparation method of self-healing waterborne polyurethane with synergistic effect of disulfide bond and multiple hydrogen bonds |
| CN113916417A (en) * | 2021-10-18 | 2022-01-11 | 天津科技大学 | Novel flexible stress sensor and preparation method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1213309A1 (en) * | 2000-12-05 | 2002-06-12 | Huntsman International Llc | Supramolecular polymer forming polymer |
| CN1869139A (en) * | 2006-05-15 | 2006-11-29 | 汕头大学 | Ultraviolet light solidfication water polyurethane acrylate paint resin and its preparation method |
| CN103483271A (en) * | 2013-09-10 | 2014-01-01 | 常州高特钛科新材料科技有限公司 | Preparation method of hydrogen bond self-assembly supramolecular photopolymerizable monomers |
| CN107216440A (en) * | 2017-06-16 | 2017-09-29 | 徐州佑季化工材料有限公司 | A kind of reversible hydrogen bond self-healing polymers and preparation method thereof |
| US20180325646A1 (en) * | 2017-03-31 | 2018-11-15 | Xeltis, Bv | Inhibition of Platelet Absorption |
| CN110061238A (en) * | 2018-03-20 | 2019-07-26 | 南方科技大学 | Water-soluble self-healing binder and preparation method thereof and lithium ion battery |
| CN110669188A (en) * | 2019-10-21 | 2020-01-10 | 南京林业大学 | Waterborne polyurethane coating capable of self-repairing through ultraviolet light and preparation method thereof |
| US10882943B2 (en) * | 2015-05-21 | 2021-01-05 | Croda International Plc | Polyurethane |
-
2020
- 2020-01-22 CN CN202010074422.9A patent/CN111303348A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1213309A1 (en) * | 2000-12-05 | 2002-06-12 | Huntsman International Llc | Supramolecular polymer forming polymer |
| CN1869139A (en) * | 2006-05-15 | 2006-11-29 | 汕头大学 | Ultraviolet light solidfication water polyurethane acrylate paint resin and its preparation method |
| CN103483271A (en) * | 2013-09-10 | 2014-01-01 | 常州高特钛科新材料科技有限公司 | Preparation method of hydrogen bond self-assembly supramolecular photopolymerizable monomers |
| US10882943B2 (en) * | 2015-05-21 | 2021-01-05 | Croda International Plc | Polyurethane |
| US20180325646A1 (en) * | 2017-03-31 | 2018-11-15 | Xeltis, Bv | Inhibition of Platelet Absorption |
| CN107216440A (en) * | 2017-06-16 | 2017-09-29 | 徐州佑季化工材料有限公司 | A kind of reversible hydrogen bond self-healing polymers and preparation method thereof |
| CN110061238A (en) * | 2018-03-20 | 2019-07-26 | 南方科技大学 | Water-soluble self-healing binder and preparation method thereof and lithium ion battery |
| CN110669188A (en) * | 2019-10-21 | 2020-01-10 | 南京林业大学 | Waterborne polyurethane coating capable of self-repairing through ultraviolet light and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| REN LIU: "Synthesis and properties of UV-curable self-healing oligomer", 《PROGRESS IN ORGANIC COATINGS》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112480350A (en) * | 2020-11-06 | 2021-03-12 | 中国科学院化学研究所 | Hydrophilic polyurethane, preparation method thereof, biological printing composite material and application |
| CN113817119A (en) * | 2021-09-28 | 2021-12-21 | 长春工业大学 | Preparation method of self-healing waterborne polyurethane with synergistic effect of disulfide bond and multiple hydrogen bonds |
| CN113916417A (en) * | 2021-10-18 | 2022-01-11 | 天津科技大学 | Novel flexible stress sensor and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111303348A (en) | Photocuring waterborne polyurethane emulsion and preparation method and application thereof | |
| CN106349412B (en) | Application of the supramolecular hydrogel based on acryloyl group glycine amide as self-repair material | |
| Fang et al. | Thermal-and mechanical-responsive polyurethane elastomers with self-healing, mechanical-reinforced, and thermal-stable capabilities | |
| Xiang et al. | Effect of soft chain length and generation number on properties of flexible hyperbranched polyurethane acrylate and its UV-cured film | |
| Zhao et al. | Reactive macromolecular micelle crosslinked highly elastic hydrogel with water-triggered shape-memory behaviour | |
| CN110615885A (en) | Ultraviolet-curable waterborne polyurethane emulsion and preparation method and application thereof | |
| CN109206634A (en) | Gelatin-based high intensity hydrogel and preparation method thereof | |
| Deng et al. | Effects of the reagent ratio on the properties of waterborne polyurethanes-acrylate for application in damping coating | |
| Zhu et al. | Processing tough supramolecular hydrogels with tunable strength of polyion complex | |
| CN109265580B (en) | Oil-resistant gutta-percha elastomer and preparation method thereof | |
| CN110092921A (en) | A kind of preparation method of the regulatable high-intensity wood quality hydrogel of mechanical property | |
| Zhang et al. | Ultra stretchable, tough and self-healable poly (acrylic acid) hydrogels cross-linked by self-enhanced high-density hydrogen bonds | |
| Wei et al. | Fabrication of castor oil-based hyperbranched urethane acrylate UV-curable coatings via thiol-ene click reactions | |
| Cui et al. | Strain hardening and highly resilient hydrogels crosslinked by chain-extended reactive pseudo-polyrotaxane | |
| CN109575317A (en) | A kind of high intensity hydrogel and preparation method thereof with pH response | |
| CN106947012A (en) | Hydrogel based on methylacryloyl glycine amide and its application as self-repair material | |
| Maiti et al. | Dynamic covalent cross-linked polymer gels through the reaction between side-chain β-keto ester and primary amine groups | |
| CN110128594B (en) | temperature/pH dual-sensitive high-strength nano composite hydrogel and preparation method thereof | |
| CN109180965B (en) | Multiple physical crosslinked hydrogel and preparation method thereof | |
| CN111139212A (en) | Preparation method of high-substituted albumin methacryloyl hydrogel for cell and tissue culture | |
| Shan et al. | Self-healing and malleable waterborne polyurethane bearing aliphatic disulfide linkages with hydrophobic branching chains | |
| CN112521625A (en) | High-modulus supramolecular polymer hydrogel based on carbamide and preparation method thereof | |
| CN116675858A (en) | Preparation method of amino-terminated hyperbranched polythioether and prepared internal crosslinking modified polyurethane | |
| Li et al. | Synthesis and properties of an efficient self-healing material based on Eucommia ulmoides gum | |
| Shi et al. | Preparation of ecofriendly water-borne polyurethane elastomer with mechanical robustness and self-healable ability based on multi-dynamic interactions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200619 |