CN114933689B - Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method - Google Patents
Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method Download PDFInfo
- Publication number
- CN114933689B CN114933689B CN202210761906.XA CN202210761906A CN114933689B CN 114933689 B CN114933689 B CN 114933689B CN 202210761906 A CN202210761906 A CN 202210761906A CN 114933689 B CN114933689 B CN 114933689B
- Authority
- CN
- China
- Prior art keywords
- lignin
- polyurethane elastomer
- isocyanate
- catalyst
- diisocyanate
- 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.)
- Active
Links
- 229920005610 lignin Polymers 0.000 title claims abstract description 120
- 229920003225 polyurethane elastomer Polymers 0.000 title claims abstract description 54
- 238000002360 preparation method Methods 0.000 title claims abstract description 22
- 239000012948 isocyanate Substances 0.000 claims abstract description 29
- 150000002513 isocyanates Chemical class 0.000 claims abstract description 29
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims abstract description 20
- 238000007731 hot pressing Methods 0.000 claims abstract description 17
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 16
- 238000001125 extrusion Methods 0.000 claims abstract description 14
- 239000003054 catalyst Substances 0.000 claims abstract description 11
- 239000000203 mixture Substances 0.000 claims abstract description 6
- 238000002156 mixing Methods 0.000 claims abstract description 4
- 238000001035 drying Methods 0.000 claims abstract description 3
- 238000006243 chemical reaction Methods 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 17
- 239000002202 Polyethylene glycol Substances 0.000 claims description 8
- 229920001223 polyethylene glycol Polymers 0.000 claims description 8
- 230000035484 reaction time Effects 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 239000003960 organic solvent Substances 0.000 claims description 4
- 229920001610 polycaprolactone Polymers 0.000 claims description 4
- 239000004632 polycaprolactone Substances 0.000 claims description 4
- 239000005057 Hexamethylene diisocyanate Substances 0.000 claims description 3
- 150000002009 diols Chemical class 0.000 claims description 3
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 claims description 3
- 229940085675 polyethylene glycol 800 Drugs 0.000 claims description 3
- ALQLPWJFHRMHIU-UHFFFAOYSA-N 1,4-diisocyanatobenzene Chemical compound O=C=NC1=CC=C(N=C=O)C=C1 ALQLPWJFHRMHIU-UHFFFAOYSA-N 0.000 claims description 2
- SBJCUZQNHOLYMD-UHFFFAOYSA-N 1,5-Naphthalene diisocyanate Chemical compound C1=CC=C2C(N=C=O)=CC=CC2=C1N=C=O SBJCUZQNHOLYMD-UHFFFAOYSA-N 0.000 claims description 2
- UPMLOUAZCHDJJD-UHFFFAOYSA-N 4,4'-Diphenylmethane Diisocyanate Chemical compound C1=CC(N=C=O)=CC=C1CC1=CC=C(N=C=O)C=C1 UPMLOUAZCHDJJD-UHFFFAOYSA-N 0.000 claims description 2
- 239000005058 Isophorone diisocyanate Substances 0.000 claims description 2
- 229920001732 Lignosulfonate Polymers 0.000 claims description 2
- 239000003513 alkali Substances 0.000 claims description 2
- 125000005442 diisocyanate group Chemical group 0.000 claims description 2
- 230000002255 enzymatic effect Effects 0.000 claims description 2
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 claims description 2
- 229920005611 kraft lignin Polymers 0.000 claims description 2
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 2
- 238000012545 processing Methods 0.000 abstract description 19
- 229920001971 elastomer Polymers 0.000 abstract description 14
- 239000000806 elastomer Substances 0.000 abstract description 14
- 239000002861 polymer material Substances 0.000 abstract description 2
- 229920013724 bio-based polymer Polymers 0.000 abstract 1
- 239000000463 material Substances 0.000 description 21
- 239000004814 polyurethane Substances 0.000 description 15
- 229920002635 polyurethane Polymers 0.000 description 14
- 238000004132 cross linking Methods 0.000 description 7
- 229920005862 polyol Polymers 0.000 description 6
- 150000003077 polyols Chemical class 0.000 description 6
- 238000002425 crystallisation Methods 0.000 description 5
- 230000008025 crystallization Effects 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 239000007788 liquid Substances 0.000 description 3
- 239000003208 petroleum Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000007071 enzymatic hydrolysis Effects 0.000 description 2
- 238000006047 enzymatic hydrolysis reaction Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 229920005906 polyester polyol Polymers 0.000 description 2
- 229920000909 polytetrahydrofuran Polymers 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 238000007634 remodeling Methods 0.000 description 2
- 238000010008 shearing Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000002028 Biomass Substances 0.000 description 1
- 239000004970 Chain extender Substances 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 229920001730 Moisture cure polyurethane Polymers 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 229920002334 Spandex Polymers 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 125000003158 alcohol group Chemical group 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000002649 leather substitute Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 229920006306 polyurethane fiber Polymers 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000004759 spandex Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- 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
- C08G18/64—Macromolecular compounds not provided for by groups C08G18/42 - C08G18/63
- C08G18/6492—Lignin containing materials; Wood resins; Wood tars; Derivatives thereof
-
- 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
- C08G18/4009—Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
- C08G18/4081—Mixtures of compounds of group C08G18/64 with other macromolecular compounds
-
- 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
- C08G18/4833—Polyethers containing oxyethylene units
-
- 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
- C08G18/73—Polyisocyanates or polyisothiocyanates acyclic
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention relates to the technical field of bio-based polymer materials, and discloses a lignin polyurethane elastomer capable of being repeatedly processed and a catalyst-free preparation method thereof, which comprises the following steps: step 1, mixing lignin and long-chain dihydric alcohol, and drying; step 2, adding isocyanate into the mixture dried in the step 1, and reacting to obtain the lignin polyurethane elastomer; step3, the lignin polyurethane elastomer is repeatedly processed and utilized in a hot-pressing or extrusion mode; the isocyanate amount is less than 1.0 based on the isocyanate index of lignin hydroxyl groups. According to the invention, the lignin polyurethane elastomer capable of being repeatedly processed is prepared under the condition of no catalyst, the obtained elastomer is remolded after hot processing, the mechanical property is obviously improved, and the better mechanical property is shown.
Description
Technical Field
The invention relates to the technical field of bio-based high polymer materials, in particular to a lignin polyurethane elastomer capable of being repeatedly processed and a catalyst-free preparation method.
Background
Polyurethane (PU) is a general polymer compound having urethane bonds as repeating units. Polyurethanes are generally obtained by polyaddition of di-or polyisocyanates with polyether polyols or polyester polyols. The earliest polyurethane is polyurethane fiber (spandex fiber) invented by the german doctor in the 30 th century of the 19 th century, and through the development of more than 80 years, the performance adjustability of polyurethane materials is wider with the diversification of the raw material structure, and the diversity of the product forms thereof is more abundant, for example, foams, synthetic leather, adhesives, fibers, elastomers, paints and the like. The polyurethane elastomer is a large application aspect of polyurethane materials, has good elasticity, toughness and dimensional stability, has good oil resistance, wear resistance, low temperature resistance and aging resistance, has certain biocompatibility, and gradually goes into the aspects of our life.
At present, the preparation of polyurethane materials mainly uses petroleum-based raw materials, the consumption of a large amount of petrochemical resources causes serious resource consumption and environmental problems, and biomass resources replace petroleum-based resources to be used for preparing polyurethane become mainstream. Lignin is used as a polyhydroxy compound, a large number of hydroxyl groups on the surface of the lignin are used as a basis for synthesizing lignin-based polyurethane, but the obtained lignin-based polyurethane is of a cross-linked network structure and is difficult to thermally process in a simple mode due to the characteristic of the polyfunctional degree of the lignin, so that the preparation of the lignin-based polyurethane capable of being simply and repeatedly processed becomes an important point of technical development.
CN113817130a discloses a solvent-free lignin-based polyurethane elastomer capable of being repeatedly processed and a preparation method thereof, lignin with specific molecular weight and short-chain polyol are prepared into lignin polyol mixed dispersion liquid, and then the lignin polyol mixed dispersion liquid reacts with polyurethane prepolymer to prepare the lignin-based polyurethane elastomer. The adopted low molecular weight lignin has high reactivity and better compatibility with polyurethane matrix, and the lignin-based polyurethane elastomer can be synthesized by using a solvent-free method, so that the lignin-based polyurethane elastomer can be recycled for multiple times and repeatedly processed and utilized, and the problems that the traditional thermosetting lignin-based polyurethane elastomer is difficult to recycle and cannot be reprocessed are solved.
CN 113754851A discloses a self-repairable lignin-containing polyurethane elastomer and a preparation method thereof, wherein the self-repairable lignin-containing polyurethane elastomer based on dynamic disulfide bonds is prepared from disulfide bond and lignin-containing liquid polyester polyol, isocyanate and a chain extender, and the repair method only needs to align and laminate a cracked or cracked sample and reheat the sample.
However, the preparation process of lignin-based polyurethane which is simply and repeatedly processed is complicated, and the preparation process can be realized only by a catalyst.
Disclosure of Invention
Aiming at the problem that the thermosetting lignin-based polyurethane elastomer cannot be subjected to thermal processing under the condition of no catalyst, the invention provides a method for preparing the lignin polyurethane elastomer capable of being repeatedly processed without a catalyst.
In order to achieve the above purpose, the invention adopts the following technical scheme:
A catalyst-free preparation method of a repeatedly-processable lignin polyurethane elastomer comprises the following steps:
Step 1, mixing lignin and long-chain dihydric alcohol, and drying;
Step 2, adding isocyanate into the mixture dried in the step 1, and reacting to obtain the lignin polyurethane elastomer;
Step 3, the lignin polyurethane elastomer is repeatedly processed and utilized in a hot-pressing or extrusion mode;
the isocyanate consumption is calculated based on the hydroxyl content of lignin and the hydroxyl content of long-chain dihydric alcohol, and the isocyanate index based on the long-chain dihydric alcohol is 1.0; the isocyanate index based on lignin hydroxyl groups is 0.4 to 1.0, but does not contain 1.0.
Since the urethane bond itself is a dynamic covalent bond, it can undergo an exchange reaction with the urethane bond in the presence of a catalyst; and directly exchange reaction with hydroxyl under the condition of no catalyst. According to the invention, lignin is adopted to partially replace petroleum-based polyol, so that isocyanate and hydroxyl react to generate urethane bonds to obtain crosslinked polyurethane, and the characteristic of lignin multi-functionality is utilized, and the excessive hydroxyl on the surface of lignin in a reaction system is caused by designing the raw material proportion, so that free hydroxyl exists in the material. In this way, the remaining hydroxyl groups are capable of undergoing an exchange reaction with urethane linkages in the absence of a catalyst (the reaction proceeds as follows, where R 1、R2、R3 is an isocyanate or other segmented structure of a polyol) imparting hot workability to the lignin-based polyurethane crosslinked network.
The amount of isocyanate used in the invention is calculated in two parts, so that the isocyanate index based on the total hydroxyl groups can be controlled in a proper range, and the change of the mechanical property and the exchange reaction of the material when the isocyanate is insufficient can be explored. When the isocyanate consumption is too low, the crosslinking degree of the material is low, a large amount of long-chain dihydric alcohol forms crystals, the mechanical property is low, and the material is fragile. When the isocyanate amount is high, the residual hydroxyl amount is low, and it is difficult to perform the exchange reaction without a catalyst.
In the mixture of lignin and long-chain dihydric alcohol, the mass ratio of lignin is 10-70%.
Preferably, the lignin mass ratio in the mixture of lignin and long-chain dihydric alcohol is 20-60%. The lignin content is too low, the crosslinking density of the product is low, a low molecular weight polymer can be formed, and long-chain dihydric alcohol has very strong crystallization capability, so that the obtained material is very fragile and has poor mechanical properties. Conversely, if the lignin content is too high, the crosslinking density of the material is high, the rigidity is strong, the toughness of the product is poor, and the elongation at break is not high.
Preferably, the lignin comprises one or more of alkali lignin, organic solvent lignin, kraft lignin, lignin sulfonate or enzymatic lignin.
Preferably, the long chain diol comprises one or more of polyethylene glycol 800, polyethylene glycol 2000, polycaprolactone diol 800, or polycaprolactone 2000.
Further preferably, the lignin is lignin which is an organic solvent, and the lignin is enzymatically hydrolyzed, and the polyalcohol is polyethylene glycol 2000 or polyethylene glycol 800. The organic solvent lignin and the enzymatic hydrolysis lignin have a complete lignin structure and high surface hydroxyl content, and the polyethylene glycol has high reactivity with lignin and isocyanate, has good compatibility with lignin, and is easy to prepare the lignin-based polyurethane elastomer by a one-step method.
The isocyanate comprises any one or more of diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, 1, 5-naphthalene diisocyanate, toluene diisocyanate and dicyclohexyl diisocyanate.
The reaction temperature in the step 2 is 80-120 ℃ and the reaction time is 20-50min.
Preferably, the reaction temperature is 85-110 ℃ and the reaction time is 20-40min. Wherein if the reaction temperature is too low, the reaction proceeds slowly, requiring a longer reaction time. If the reaction temperature is too high, the reaction is extremely severe, and the reaction can be completed without uniformly stirring the materials.
The hot pressing or extrusion temperature in the step 3 is 150-200 ℃ and the reaction time is 20-60min.
Preferably, the processing temperature is 160-190 ℃ and the reaction time is 20-50min. The processing temperature is too low, the reaction is slow, longer reaction time is needed, and the processing fluidity of the material is poor. If the reaction temperature is too high and the processing time is long, the material is at risk of ageing.
The lignin polyurethane elastomer which can be repeatedly processed and is prepared by the preparation method has the tensile modulus of 17-351MPa, the tensile strength of 2.5-12.5MPa and the elongation at break of 11-86%;
the mechanical property of the lignin polyurethane elastomer is improved after hot pressing or extrusion, the tensile modulus is 21-649MPa, the tensile strength is 7.5-19.5MPa, and the elongation at break is 36-147%. The lignin polyurethane elastomer prepared by the invention shows better mechanical properties after thermal processing.
Compared with the prior art, the invention has the following beneficial effects:
(1) The lignin polyurethane elastomer capable of being repeatedly processed is prepared under the condition of no catalyst, and the obtained elastomer is remolded after hot processing through regulating and controlling the raw material proportion and designing the preparation process, so that the elastomer has more excellent mechanical properties.
(2) The lignin polyurethane elastomer which can be repeatedly processed is prepared by adopting the one-step method, the reaction condition is mild, the preparation method is simple, the use of a catalyst is avoided, and the production cost is reduced.
Drawings
FIG. 1 is a schematic representation of the synthesis and remodeling process of lignin-based polyurethane elastomers of the present invention.
FIG. 2 is a graph of tensile properties of lignin-based polyurethane elastomer in example 1.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. Modifications and equivalents will occur to those skilled in the art upon understanding the present teachings without departing from the spirit and scope of the present teachings.
Raw materials used in the following embodiments are all purchased on the market, and a schematic diagram of the synthesis process and the remodeling process of the lignin-based polyurethane elastomer in the present invention is shown in fig. 1.
Example 1
Step 1, weighing 50 parts of polyethylene glycol 2000, vacuumizing at 100 ℃ to remove water, adding 50 parts of enzymolysis lignin, stirring for 10min until the lignin is uniformly dispersed, adding hexamethylene diisocyanate (the isocyanate index based on lignin hydroxyl is 0.8, the isocyanate index based on long-chain dihydric alcohol is 1.0, then reacting at 100 ℃ for 30min to obtain the expected lignin-based polyurethane elastomer, and hot-pressing to obtain the lignin-based polyurethane elastomer sheet.
And 2-1, shearing the lignin-based polyurethane elastomer sheet prepared in the step 1, and hot-pressing for 30min at 180 ℃ and 10MPa to obtain the remolded lignin-based polyurethane elastomer.
And 2-2, shearing the lignin-based polyurethane elastomer sheet prepared in the step 1, adding the sheet into an extruder at 180 ℃ for extrusion processing, discharging, and then continuously hot-pressing for 30min under 10MPa to obtain the extruded lignin-based polyurethane elastomer.
Cutting the prepared lignin-based polyurethane into dumbbell-shaped tensile bars, and testing by using an international standard ISO527-1:2012 and using a universal style stretcher to find that the original lignin-based polyurethane elastomer prepared in the step 1 has a modulus of 70MPa, a tensile strength of 5.8MPa and an elongation at break of 56%; the elastomer subjected to remolding and hot pressing in the step 2-1 has a modulus of 75MPa, a tensile strength of 6.3MPa and an elongation at break of 61%; the modulus of the elastomer after extrusion processing in step 2-2 is 139MPa, the tensile strength is 16.4MPa, the elongation at break is 100%, and the tensile curve is shown in figure 2.
The mechanical properties of the material are slightly improved after the hot pressing treatment, and the tensile modulus, the tensile strength and the elongation at break of the material are greatly improved after the extrusion hot pressing remolding, so that the effect is remarkable.
Example 2
The preparation method according to example 1 was followed, wherein the lignin-based polyurethane elastomer was obtained by substituting 0.4 for the lignin hydroxyl-based isocyanate index of 0.8, and the properties thereof were tested by the same method as above, and the original lignin-based polyurethane elastomer was found to have a modulus of 21MPa, a tensile strength of 3.3MPa and an elongation at break of 76%; the elastomer after remolding hot-pressing processing has a modulus of 26MPa, a tensile strength of 4.1MPa and an elongation at break of 74%; the modulus of the elastomer after extrusion processing is 87MPa, the tensile strength is 7.9MPa, and the elongation at break is 98%.
Comparative example 1
The preparation method according to example 1 was followed, wherein the lignin hydroxyl-based isocyanate index of 0.8 was replaced with 1.0, to obtain a lignin-based polyurethane elastomer, and various properties thereof were tested by the same method as above, and it was found that the original lignin-based polyurethane elastomer had a modulus of 99MPa, a tensile strength of 6.5MPa, and an elongation at break of 52%; the elastomer after remolding hot-pressing processing has a modulus of 56MPa, a tensile strength of 4.3MPa and an elongation at break of 46%; the modulus of the elastomer after extrusion processing is 67MPa, the tensile strength is 5.8MPa, and the elongation at break is 48%.
The reason why the performance does not deteriorate after the processing of the ratio is that the amount of the hydroxyl group remaining is small in the case where the isocyanate is 1.0, and the exchange reaction is insufficient, and the performance is lowered.
Example 3
According to the preparation method of example 1, 50 parts of the lignin is replaced by 20 parts of the lignin-based polyurethane elastomer, and the properties of the lignin-based polyurethane elastomer are tested by the same method, so that the original lignin-based polyurethane elastomer has a modulus of 253MPa, a tensile strength of 7.7MPa and an elongation at break of 76%; the elastomer after remolding hot-pressing processing has a modulus of 261MPa, a tensile strength of 7.9MPa and an elongation at break of 56%; the modulus of the elastomer after extrusion processing is 348MPa, the tensile strength is 8.3MPa, and the elongation at break is 34%. The lignin content is reduced, the crosslinking density is reduced, polyethylene glycol crystallization is difficult to inhibit, and the local crystallization of the material improves the modulus and strength of the material, but the elongation at break is reduced.
Example 4
According to the preparation method of the embodiment 1, 50 parts of the lignin is replaced by 60 parts of the lignin-based polyurethane elastomer by enzymolysis, and various properties of the lignin-based polyurethane elastomer are tested by the same method, wherein the original lignin-based polyurethane elastomer has a modulus of 341MPa, a tensile strength of 10.5MPa and an elongation at break of 25%; the elastomer after remolding hot-pressing processing has a modulus of 385MPa, a tensile strength of 11.2MPa and an elongation at break of 21%; the modulus of the elastomer after extrusion processing is 649MPa, the tensile strength is 19.5MPa, and the elongation at break is 36%.
The lignin content is improved, the crosslinking density is improved, and the rigidity of the material is improved. Meanwhile, due to the multi-aromatic ring structure of lignin, the rigidity is high, the strength of the material is improved along with the improvement of lignin content, but the elongation at break is reduced, if the lignin dosage is further increased, the comprehensive performance of the final product is possibly poor.
Comparative example 2
According to the preparation method of the example 1, 50 parts of the enzymatic hydrolysis lignin is replaced by 10 parts, and the low molecular weight polymer formed by the low lignin content and the low crosslinking density has very strong crystallization capability due to the polyethylene glycol, so that the finally obtained material is very fragile and basically has no mechanical property.
Comparative example 3
According to the preparation method of the example 1, wherein the isocyanate index based on lignin hydroxyl groups is replaced by 0.2, the material crosslinking density is extremely low due to the excessively low isocyanate usage, and the formed polymer has a large amount of crystallization and lignin which does not participate in the reaction due to the low molecular weight, and the material has basically no mechanical property.
Comparative example 4
The preparation was according to example 1, wherein polyethylene glycol 2000 was replaced by polytetrahydrofuran glycol. In the process of water removal and lignin mixing, the polytetrahydrofuran has stronger hydrophobicity and rigidity, has poorer compatibility with lignin, has layering phenomenon, and cannot normally carry out homogeneous synthetic experiments. Therefore, the long-chain dihydric alcohol of the application is preferably flexible long-chain dihydric alcohol, and the dihydric alcohol with excessive rigid groups in the structure is not preferably selected.
Claims (4)
1. The catalyst-free preparation method of the repeatedly-processable lignin polyurethane elastomer is characterized by comprising the following steps of:
Step 1, mixing lignin and long-chain dihydric alcohol, and drying;
Step 2, adding isocyanate into the mixture dried in the step 1, and reacting to obtain the lignin polyurethane elastomer;
Step 3, the lignin polyurethane elastomer is repeatedly processed and utilized in a hot-pressing or extrusion mode; the hot pressing or extrusion temperature in the step 3 is 150-200 ℃ and the treatment time is 20-60min;
The isocyanate consumption is calculated based on the sum of the lignin and the hydroxyl content of the long-chain dihydric alcohol, and the isocyanate index based on the long-chain dihydric alcohol is 1.0; isocyanate index based on lignin hydroxyl groups of 0.4 to 1.0, but not 1.0;
In the mixture of lignin and long-chain dihydric alcohol, the mass ratio of lignin is 20-60%;
The long-chain dihydric alcohol comprises one or more of polyethylene glycol 800, polyethylene glycol 2000, polycaprolactone diol 800 or polycaprolactone 2000;
The isocyanate comprises any one or more of diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, 1, 5-naphthalene diisocyanate, toluene diisocyanate and dicyclohexyl diisocyanate.
2. The method for preparing the reproducible lignin polyurethane elastomer without catalyst according to claim 1, wherein the lignin comprises one or more of alkali lignin, organic solvent lignin, kraft lignin, lignin sulfonate or enzymatic lignin.
3. The method for preparing the catalyst-free lignin polyurethane elastomer capable of being repeatedly processed according to claim 1 wherein the reaction temperature in the step 2 is 80-120 ℃ and the reaction time is 20-50min.
4. A reworkable lignin polyurethane elastomer produced according to the process of any one of claims 1 to 3 wherein the lignin polyurethane elastomer has a tensile modulus of 17 to 351MPa, a tensile strength of 2.5 to 12.5MPa and an elongation at break of 11 to 86%;
The lignin polyurethane elastomer has improved mechanical properties after hot pressing or extrusion, a tensile modulus of 21-649MPa, a tensile strength of 7.5-19.5MPa and an elongation at break of 36-147%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210761906.XA CN114933689B (en) | 2022-06-29 | 2022-06-29 | Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210761906.XA CN114933689B (en) | 2022-06-29 | 2022-06-29 | Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114933689A CN114933689A (en) | 2022-08-23 |
| CN114933689B true CN114933689B (en) | 2024-05-31 |
Family
ID=82867951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210761906.XA Active CN114933689B (en) | 2022-06-29 | 2022-06-29 | Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114933689B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115677972A (en) * | 2022-11-21 | 2023-02-03 | 华南理工大学 | Tough type light-operated self-repairing lignin-based polyurethane and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106432684A (en) * | 2016-09-14 | 2017-02-22 | 中国林业科学研究院林产化学工业研究所 | Self-catalytic anacardol/lignin-based polyurethane foam and preparation method thereof |
| CN109485824A (en) * | 2018-10-12 | 2019-03-19 | 华南理工大学 | A kind of thermosetting property lignin-base polyurethane elastomer of recyclable processing and preparation method thereof |
| CN112980175A (en) * | 2021-02-07 | 2021-06-18 | 陕西科技大学 | Preparation method of polyurethane/lignin composite material |
| CN113817130A (en) * | 2021-09-26 | 2021-12-21 | 华南理工大学 | Solvent-free lignin-based polyurethane elastomer capable of being repeatedly processed and preparation method thereof |
| CN114478984A (en) * | 2021-12-30 | 2022-05-13 | 广东粤港澳大湾区黄埔材料研究院 | High-temperature-aging-resistant rigid polyurethane elastomer and preparation method thereof |
-
2022
- 2022-06-29 CN CN202210761906.XA patent/CN114933689B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106432684A (en) * | 2016-09-14 | 2017-02-22 | 中国林业科学研究院林产化学工业研究所 | Self-catalytic anacardol/lignin-based polyurethane foam and preparation method thereof |
| CN109485824A (en) * | 2018-10-12 | 2019-03-19 | 华南理工大学 | A kind of thermosetting property lignin-base polyurethane elastomer of recyclable processing and preparation method thereof |
| CN112980175A (en) * | 2021-02-07 | 2021-06-18 | 陕西科技大学 | Preparation method of polyurethane/lignin composite material |
| CN113817130A (en) * | 2021-09-26 | 2021-12-21 | 华南理工大学 | Solvent-free lignin-based polyurethane elastomer capable of being repeatedly processed and preparation method thereof |
| CN114478984A (en) * | 2021-12-30 | 2022-05-13 | 广东粤港澳大湾区黄埔材料研究院 | High-temperature-aging-resistant rigid polyurethane elastomer and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| "Lignin-containing polyurethane elastomers with enhanced mechanical properties via hydrogen bond interactions";Nan Sun等;《International Journal of Biological Macromolecules》;1-8 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114933689A (en) | 2022-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113817130B (en) | Solvent-free lignin-based polyurethane elastomer capable of being repeatedly processed and preparation method thereof | |
| CN109485824A (en) | A kind of thermosetting property lignin-base polyurethane elastomer of recyclable processing and preparation method thereof | |
| CN114933689B (en) | Lignin polyurethane elastomer capable of being repeatedly processed and catalyst-free preparation method | |
| CN110183615B (en) | Environment-friendly polyurethane elastomer containing lignin | |
| CN109988537B (en) | Starch modified polyurethane adhesive and preparation method thereof | |
| JP7083825B2 (en) | Method for Producing Biopolyester Polyol, Biopolyester Polyol and Biopolyurethane Resin | |
| CN113754857A (en) | Polyurethane elastomer for quickly-formed low-temperature-resistant shoe material and preparation method thereof | |
| CN114316196B (en) | Hydrolysis-resistant polyurethane damping material and preparation method and application thereof | |
| CN115109220A (en) | Preparation method of hydrolysis-resistant thermoplastic polyurethane elastomer material | |
| CN111607062B (en) | Biomass polyurethane foam material and preparation method thereof | |
| CN115073697B (en) | Bio-based polyurethane elastomer and preparation method thereof | |
| CN109206589B (en) | Preparation method of pyrolysis lignin and lignin-based polyurethane rigid foam | |
| CN114426805B (en) | Preparation method of hydrolysis-resistant polyurethane hot melt adhesive | |
| CN110283290B (en) | Hydrolysis-resistant polyurethane elastomer and preparation method thereof | |
| CN113912811A (en) | Organic silicon/castor oil double-modified waterborne polyurethane resin and preparation method and application thereof | |
| CN113861363A (en) | Preparation method of anti-ultraviolet transparent lignin-based polyurethane elastomer | |
| CN113583206A (en) | Thermal insulation material prepared by degrading waste polyurethane and preparation method thereof | |
| CN112831011A (en) | Crosslinkable network-structure polyurethane emulsion and preparation method thereof | |
| CN115260438B (en) | Preparation method of soft polyurethane elastomer | |
| CN117924641A (en) | Hydrophobic oil-resistant degradable lignin-based waterborne polyurethane for paper coating and preparation method thereof | |
| CN113549194B (en) | Process for producing crosslinked polyurethane materials | |
| KR102008756B1 (en) | Thermoplastic Polyurethane Composition and method thereof | |
| CN116769126A (en) | Lignin-based polyester elastomer with high bio-based content, high strength and high toughness and preparation method thereof | |
| CN117844060A (en) | Microcrystalline cellulose-based rubber and preparation method thereof | |
| CN115353654A (en) | High-weather-resistance water-based polyurethane adhesive film and manufacturing method thereof |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |