CN109705300B

CN109705300B - Self-repairing polyurethane and preparation method thereof

Info

Publication number: CN109705300B
Application number: CN201811582067.5A
Authority: CN
Inventors: 游正伟; 张璐之; 刘增贺
Original assignee: Donghua University
Current assignee: Donghua University
Priority date: 2018-12-24
Filing date: 2018-12-24
Publication date: 2021-05-11
Anticipated expiration: 2038-12-24
Also published as: CN109705300A

Abstract

The invention relates to self-repairing polyurethane and a preparation method thereof. The polyurethane disclosed by the invention has good mechanical properties and excellent self-repairing performance; the preparation method is simple, the cost is low, and the market application prospect is good.

Description

Self-repairing polyurethane and preparation method thereof

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to self-repairing polyurethane and a preparation method thereof.

Background

Polyurethane refers to a class of polymers containing a large amount of urethane in the molecular structure, also called polyurethane, which is also known as polyurethane, and is also called Polyurethane (PU) for short. Because the performance of the polyurethane material can be realized by adjusting the molecular structure of the polyurethane material, and the method is simple, the polyurethane material is widely applied to the fields of buildings, automobiles, electronics, packaging, shoe making and the like. In the actual use process, the polyurethane material is inevitably damaged by external force to generate defects, and the related performance of the polyurethane material is lost or reduced, so that the service life of the material is shortened, the safety of the material is reduced, and the maintenance cost of the material is increased. However, most of the currently used polyurethane materials cannot be repaired after the defects are generated, and some of the polyurethane materials can be repaired, but the repairing process requires additional healing agent or energy (such as heat, light, pressure and the like) input, which greatly limits the practical use requirements. In addition, there are few reports that the polyurethane material capable of self-repairing spontaneously (without additional healing agent or energy) at room temperature is also conditioned by the compromise of mechanical properties, and the problems of high preparation cost, complex synthesis process and the like are accompanied. Therefore, the preparation of the polyurethane material with self-repairing function and excellent mechanical property has important significance.

Disclosure of Invention

The technical problem to be solved by the invention is to provide self-repairing polyurethane and a preparation method thereof, wherein the self-repairing polyurethane utilizes the synergistic effect of various dynamic bonds, firstly comprises an inherent dynamic hydrogen bond system in a polyurethane system, secondly is a dynamic covalent bond by introducing an oxime urethane bond generated by the reaction of an oxime group and an isocyanate group, and finally can form a dynamic metal-coordination bond by introducing metal ions to coordinate with oxime; the preparation cost is low, the mechanical property is good, and the room temperature spontaneous self-repairing performance is excellent.

The invention provides self-repairing polyurethane which comprises the following raw materials in parts by weight:

dioxime: 1-10 parts;

polyether polyol: 0-100 parts;

polyester polyol: 0-100 parts;

polyisocyanate: 5-100 parts;

a crosslinking agent: 0-5 parts;

metal salt: 0-10 parts;

catalyst: 0-1 part;

solvent: 0-500 parts.

Preferably, the dioxime (a substance having a compound structure containing two or more C ═ N — OH groups) is one or more of dimethylglyoxime, furildioxime, pyruvaldehyde dioxime, 2, 4-pentanedione dioxime, furildioxime, 1, 4-benzoquinone dioxime, diphenylglyoxime, 1, 2-cyclohexanedione dioxime, acenaphthenone dioxime, and dichloroglyoxime.

Preferably, the polyether polyol (ether substance containing two or more-OH groups in the compound structure) is one or more of polytetrahydrofuran ether glycol, polypropylene glycol, polyethylene glycol and polyglycerol; the polyether polyol has a weight average molecular weight of 500-10000.

Preferably, the polyester polyol (ester substance containing two or more-OH groups in the structure of the compound) is one or more of poly (hexanediol adipate) diol, poly (butanediol adipate) diol, poly (propylene adipate) diol, poly (ethylene adipate) diol, poly (butylene phthalate) diol, polycaprolactone diol and polycaprolactone triol; the weight average molecular weight of the polyester polyol is 500-10000.

Preferably, the polyisocyanate (a compound having two or more-NCO groups in the structure) is one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, L-lysine triisocyanate, and polymethylene polyphenyl polyisocyanate.

Preferably, the cross-linking agent is one or more of glycerol, water, 1,2, 3-butanetriol, 1,2, 4-butanetriol, pentaerythritol, diethanolamine, trimethylolpropane, sorbitol, melamine, diethylenetriamine and castor oil.

Preferably, the metal in the metal salt is selected from the group consisting of hydrochloride, sulfate, bromide, acetate, nitrate, citrate, methanesulfonate, acetylacetonate, fluoroborate, difluoride, gluconate, hydroxycarbonate, sulfide, thiocyanate, iodide, niobate, ethoxide, phosphate, oxalate, trifluoroacetate, tetracyanophosphate, pyrophosphate, stearate, bis (trifluoromethanesulfonic) imide, trifluoromethanesulfonate, thiophene-2-formate, tetrahydrate, diethyldithiocarbonylate, cyanide, diethylhexanoate, ethylacetoacetate, ammonium sulfate hexahydrate, perchlorate, sodium ethylene diamine tetraacetate, Bis (triphenylphosphine) borohydride, tetrakis (acetonitrile) tetrafluoroborate, bis (hexafluoroacetylacetonato) salt, octadecenoate, acrylate, methacrylate, pyrophosphate, isopropoxide, bis (1-hydroxy-1H-pyridine-2-thiosulphate-O, S) salt, methoxide or fluoride.

Preferably, the catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether, N-ethyl morpholine and triethylenediamine.

Preferably, the solvent is one or more of acetone, tetrahydrofuran, N-dimethylformamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform.

The invention also provides a preparation method of the self-repairing polyurethane, which comprises the following steps:

(1) dissolving 1-10 parts of dioxime, 0-100 parts of polyether polyol, 0-100 parts of polyester polyol and 0-5 parts of cross-linking agent in 0-500 parts of solvent;

(2) then adding 5-100 parts of polyisocyanate and 0-1 part of catalyst, reacting for 0.5-1 hour at 40-70 ℃, then adding 0-10 parts of metal salt, and further reacting for 0.5-2 hours at 50-75 ℃;

(3) and finally, transferring the mixture into a vacuum oven, reacting for 20-50 hours at the temperature of 60-90 ℃, and vacuumizing until no bubbles appear to obtain the product.

Advantageous effects

The self-repairing polyurethane disclosed by the invention utilizes the synergistic effect of various dynamic bonds, firstly comprises an inherent dynamic hydrogen bond system in a polyurethane system, secondly is a dynamic covalent bond by introducing an oxime urethane bond generated by the reaction of an oxime group and an isocyanate group, and finally can form a dynamic metal-coordination bond by introducing metal ions to coordinate with oxime. Therefore, the self-repairing polyurethane disclosed by the invention has good mechanical properties and excellent room-temperature self-repairing performance, and no extra repairing agent or energy (heating, illumination, pressure and the like) is required to be input in the repairing process; the polyurethane material has simple preparation method and low preparation cost; the material composition and the structure of the material have strong controllability, and the material has good market application prospect.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Example 1

Dissolving 2 parts of dimethylglyoxime, 20 parts of polytetrahydrofuran ether glycol (Mn 1000) and 0.4 part of glycerol in 50 parts of acetone; then adding 10 parts of isophorone diisocyanate and 0.3 part of dibutyltin dilaurate, reacting for 0.5 hour at 55 ℃, adding 0.5 part of copper chloride, and further reacting for 0.5 hour at 60 ℃; and transferring the reaction liquid into a vacuum oven, reacting for 35 hours at 75 ℃, and vacuumizing until no bubbles appear, thereby obtaining the self-repairing polyurethane.

And (4) inspecting the mechanical property and the self-repairing property of the material by using an electronic universal material testing machine. The strength of the polyurethane material is 14.8 Mpa; the materials are completely cut off and spliced together and placed at 25 ℃ for 40 hours under the state of no external force, and the strength is 8 MPa.

Example 2

Dissolving 2 parts of dimethylglyoxime, 20 parts of polytetrahydrofuran ether glycol (Mn 1000) and 0.4 part of glycerol in 50 parts of acetone; then adding 10 parts of isophorone diisocyanate and 0.3 part of dibutyltin dilaurate, reacting at 55 ℃ for 0.5 hour, adding 1 part of bis (trifluoromethanesulfonic acid) copper imide, and further reacting at 60 ℃ for 0.5 hour; and transferring the reaction liquid into a vacuum oven, reacting for 35 hours at 75 ℃, and vacuumizing until no bubbles appear, thereby obtaining the self-repairing polyurethane.

And (4) inspecting the mechanical property and the self-repairing property of the material by using an electronic universal material testing machine. The strength of the polyurethane material is 11.5 MPa; the materials are completely cut off and spliced together and placed at 25 ℃ for 40 hours under the state of no external force, and the strength is 8.1 Mpa.

Example 3

Dissolving 2 parts of dimethylglyoxime, 20 parts of polytetrahydrofuran ether glycol (Mn 1000) and 0.4 part of glycerol in 50 parts of acetone; then adding 10 parts of isophorone diisocyanate and 0.3 part of dibutyltin dilaurate, reacting at 55 ℃ for 0.5 hour, and further reacting at 60 ℃ for 0.5 hour; and transferring the reaction liquid into a vacuum oven, reacting for 35 hours at 75 ℃, and vacuumizing until no bubbles appear, thereby obtaining the self-repairing polyurethane.

And (4) inspecting the mechanical property and the self-repairing property of the material by using an electronic universal material testing machine. The strength of the polyurethane material is 6.8 Mpa; the materials are completely cut off and spliced together and placed at 25 ℃ for 40 hours under the state of no external force, and the strength is 3.7 MPa.

The self-repairing polyurethane material obtained in the embodiments 1-3 can perform spontaneous self-repairing at room temperature, and the original strength and the strength after self-repairing of the material can be adjusted by adjusting different formulas, so as to meet different use requirements.

To illustrate the role that dioximes play in materials, comparative examples were designed, the formulation of which was modified based on the formulation of example 3. While keeping the other components of example 3 unchanged, the dimethylglyoxime component was subtracted from the comparative example and the amount of polytetrahydrofuran ether glycol (Mn 1000) was increased to keep the total number of hydroxyl groups in the system unchanged, as follows:

comparative example

Dissolving 40 parts of polytetrahydrofuran ether glycol (Mn 1000) and 0.4 part of glycerol in 50 parts of acetone; then adding 10 parts of isophorone diisocyanate and 0.3 part of dibutyltin dilaurate, reacting at 55 ℃ for 0.5 hour, and further reacting at 60 ℃ for 0.5 hour; and transferring the reaction liquid into a vacuum oven, reacting for 35 hours at 75 ℃, and vacuumizing until no bubbles appear, thereby obtaining the polyurethane of the comparative example.

And (4) inspecting the mechanical property and the self-repairing property of the material by using an electronic universal material testing machine. The strength of the polyurethane material is 4.1 Mpa; the materials are completely cut off and spliced together and placed at 25 ℃ for 40 hours under the state of no external force, and the strength is 1.0 MPa.

The results of the example 3 and the comparative example show that the introduction of the dioxime component effectively improves the self-healing efficiency of the material while enhancing the mechanical strength of the material.

Claims

1. A self-repairing polyurethane, which is characterized in that: the raw materials consist of the following components in parts by weight:

2. a preparation method of self-repairing polyurethane comprises the following steps:

dissolving 2 parts of dimethylglyoxime, 20 parts of polytetrahydrofuran ether glycol and 0.4 part of glycerol in 50 parts of acetone; then adding 10 parts of isophorone diisocyanate and 0.3 part of dibutyltin dilaurate, reacting for 0.5 hour at 55 ℃, adding 0.5 part of copper chloride, and further reacting for 0.5 hour at 60 ℃; and transferring the reaction liquid into a vacuum oven, reacting for 35 hours at 75 ℃, and vacuumizing until no bubbles appear, thereby obtaining the self-repairing polyurethane.