CN115677971A - Polyurethane prepolymer and preparation method thereof - Google Patents
Polyurethane prepolymer and preparation method thereof Download PDFInfo
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- CN115677971A CN115677971A CN202211446256.6A CN202211446256A CN115677971A CN 115677971 A CN115677971 A CN 115677971A CN 202211446256 A CN202211446256 A CN 202211446256A CN 115677971 A CN115677971 A CN 115677971A
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- 229920001730 Moisture cure polyurethane Polymers 0.000 title claims abstract description 104
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 229920005862 polyol Polymers 0.000 claims abstract description 138
- 150000003077 polyols Chemical class 0.000 claims abstract description 138
- 239000012948 isocyanate Substances 0.000 claims abstract description 85
- 150000002513 isocyanates Chemical class 0.000 claims abstract description 85
- 238000006243 chemical reaction Methods 0.000 claims abstract description 49
- 239000000203 mixture Substances 0.000 claims abstract description 47
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims abstract description 28
- 239000006087 Silane Coupling Agent Substances 0.000 claims abstract description 25
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 40
- 229920000570 polyether Polymers 0.000 claims description 40
- 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 22
- 238000000034 method Methods 0.000 claims description 19
- 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 11
- 239000005062 Polybutadiene Substances 0.000 claims description 9
- 229920002857 polybutadiene Polymers 0.000 claims description 9
- 229920001610 polycaprolactone Polymers 0.000 claims description 9
- 239000004632 polycaprolactone Substances 0.000 claims description 9
- 229920000515 polycarbonate Polymers 0.000 claims description 9
- 239000004417 polycarbonate Substances 0.000 claims description 9
- 229920000909 polytetrahydrofuran Polymers 0.000 claims description 9
- 229920005906 polyester polyol Polymers 0.000 claims description 8
- 239000005057 Hexamethylene diisocyanate Substances 0.000 claims description 7
- 239000005058 Isophorone diisocyanate Substances 0.000 claims description 7
- 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 7
- 229920000747 poly(lactic acid) Polymers 0.000 claims description 6
- 239000004626 polylactic acid Substances 0.000 claims description 6
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims 1
- 239000000178 monomer Substances 0.000 abstract description 30
- 125000001261 isocyanato group Chemical group *N=C=O 0.000 description 18
- 230000000052 comparative effect Effects 0.000 description 16
- TZZGHGKTHXIOMN-UHFFFAOYSA-N 3-trimethoxysilyl-n-(3-trimethoxysilylpropyl)propan-1-amine Chemical compound CO[Si](OC)(OC)CCCNCCC[Si](OC)(OC)OC TZZGHGKTHXIOMN-UHFFFAOYSA-N 0.000 description 11
- 238000012360 testing method Methods 0.000 description 10
- 238000003860 storage Methods 0.000 description 9
- 239000004814 polyurethane Substances 0.000 description 8
- 229920005989 resin Polymers 0.000 description 8
- 239000011347 resin Substances 0.000 description 8
- 229920002635 polyurethane Polymers 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- XLJMAIOERFSOGZ-UHFFFAOYSA-N anhydrous cyanic acid Natural products OC#N XLJMAIOERFSOGZ-UHFFFAOYSA-N 0.000 description 6
- 239000004359 castor oil Substances 0.000 description 6
- 235000019438 castor oil Nutrition 0.000 description 6
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 description 6
- UUEWCQRISZBELL-UHFFFAOYSA-N 3-trimethoxysilylpropane-1-thiol Chemical compound CO[Si](OC)(OC)CCCS UUEWCQRISZBELL-UHFFFAOYSA-N 0.000 description 5
- 125000003368 amide group Chemical group 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- JQVDAXLFBXTEQA-UHFFFAOYSA-N dibutylamine Chemical compound CCCCNCCCC JQVDAXLFBXTEQA-UHFFFAOYSA-N 0.000 description 4
- 239000012086 standard solution Substances 0.000 description 4
- 229920001187 thermosetting polymer Polymers 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 229920002396 Polyurea Polymers 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 235000019198 oils Nutrition 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 150000005846 sugar alcohols Polymers 0.000 description 3
- RUELTTOHQODFPA-UHFFFAOYSA-N toluene 2,6-diisocyanate Chemical compound CC1=C(N=C=O)C=CC=C1N=C=O RUELTTOHQODFPA-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 238000007086 side reaction Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- FRPHFZCDPYBUAU-UHFFFAOYSA-N Bromocresolgreen Chemical compound CC1=C(Br)C(O)=C(Br)C=C1C1(C=2C(=C(Br)C(O)=C(Br)C=2)C)C2=CC=CC=C2S(=O)(=O)O1 FRPHFZCDPYBUAU-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000004831 Hot glue Substances 0.000 description 1
- 235000019482 Palm oil Nutrition 0.000 description 1
- 235000019483 Peanut oil Nutrition 0.000 description 1
- 235000019484 Rapeseed oil Nutrition 0.000 description 1
- 235000019486 Sunflower oil Nutrition 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- WDJHALXBUFZDSR-UHFFFAOYSA-M acetoacetate Chemical compound CC(=O)CC([O-])=O WDJHALXBUFZDSR-UHFFFAOYSA-M 0.000 description 1
- 238000007259 addition reaction Methods 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 235000012343 cottonseed oil Nutrition 0.000 description 1
- 239000002385 cottonseed oil Substances 0.000 description 1
- 230000001626 effect on respiratory system Effects 0.000 description 1
- 230000002500 effect on skin Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 231100000206 health hazard Toxicity 0.000 description 1
- 231100000086 high toxicity Toxicity 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000199 molecular distillation Methods 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- NKZQKINFDLZVRY-UHFFFAOYSA-N n-butylbutan-1-amine;toluene Chemical compound CC1=CC=CC=C1.CCCCNCCCC NKZQKINFDLZVRY-UHFFFAOYSA-N 0.000 description 1
- 239000002540 palm oil Substances 0.000 description 1
- 239000000312 peanut oil Substances 0.000 description 1
- 239000011527 polyurethane coating Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 210000002345 respiratory system Anatomy 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 239000003549 soybean oil Substances 0.000 description 1
- 235000012424 soybean oil Nutrition 0.000 description 1
- 230000004936 stimulating effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000002600 sunflower oil Substances 0.000 description 1
- 238000005829 trimerization reaction Methods 0.000 description 1
Landscapes
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention provides a preparation method of a polyurethane prepolymer, which comprises the following steps: providing a first polyol, a second polyol, an isocyanate, and a silane coupling agent; carrying out a first reaction on the first polyol and the isocyanate to obtain a first mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1; carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1; the silane coupling agent and the second mixture are subjected to a third reaction to obtain the polyurethane prepolymer, and the problem of high content of free isocyanate monomers in the polyurethane prepolymer is solved. The invention also provides a polyurethane prepolymer.
Description
Technical Field
The invention relates to the technical field of polyurethane, in particular to a polyurethane prepolymer and a preparation method thereof.
Background
Polyurethane prepolymers have many applications in polyurethane industrial products, including polyurethane casting, polyurethane foaming, polyurethane coating, PUR hot melt adhesives, curing agent components of two-component polyurethane adhesives, etc., however, in the process of forming polyurethane prepolymers, the use of excessive molar amounts of isocyanate monomers may leave a portion of isocyanate monomers, and free isocyanate monomers have high toxicity, which may lead to potential industrial hygiene problems.
The polyurethane prepolymer with low free isocyanate monomer has the advantages of low viscosity, long in-kettle service life, long storage life and the like. The method for reducing the unreacted isocyanate monomer in the polyurethane prepolymer comprises a chemical synthesis method, a molecular sieve, solvent extraction, a film evaporator and molecular distillation. The chemical synthesis method commonly used at present is not very effective, and U.S. Pat. No. 5,5925781A discloses a method for reducing free isocyanate monomer, which comprises the steps of reacting 2,4-TDI with polyester polyol having a molecular weight range of 3000-8000, introducing liquid diphenylmethane diisocyanate (MDI) to react to remove excess alcohol, and finally removing free 2,4-TDI with small molecular methanol, but the activity of 2,6-TDI is lower than that of 2,4-TDI, so the method has poor effect on TDI80 raw materials commonly used in industry, and polyurethane prepolymer prepared by using polyester polyol having a large molecular weight has large viscosity and low NCO group content. Chinese patent publication No. CN1424345A discloses a method for preparing a polyurethane curing agent with low free toluene diisocyanate, which adds a step of reaction on the basis of the first stage addition reaction, introduces a catalyst to remove free TDI by a trimerization method, and when the final product has a solid content of 50%, the NCO group content is 7-9%, and the free TDI content is 1.0-2.0%. Chinese patent publication No. CN101456940A discloses a synthesis method for preparing a solvent type polyurethane curing agent with low free toluene diisocyanate content, which introduces acetoacetate with lower reaction activity than hydroxyl to eliminate free TDI at the second stage, and uses the synthesis method to produce polyurethane prepolymer in order to meet the environmental protection requirement at present, but the obtained polyurethane prepolymer has the disadvantages of low NCO group content, large viscosity, short storage time and free isocyanate monomer content higher than 1.0%, and the polyurethane prepolymer is difficult to reach high solid content.
Therefore, it is necessary to develop a polyurethane prepolymer and a method for preparing the same to avoid the above problems in the prior art.
Disclosure of Invention
The invention aims to provide a polyurethane prepolymer and a preparation method thereof, which solve the problem of high content of free isocyanate monomer in the polyurethane prepolymer.
In order to achieve the purpose, the preparation method of the polyurethane prepolymer comprises the following steps:
s0: providing a first polyol, a second polyol, an isocyanate, and a silane coupling agent;
s1: carrying out a first reaction on the first polyol and the isocyanate to obtain a first mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1;
s2: carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1;
s3: and carrying out a third reaction on the silane coupling agent and the second mixture to obtain the polyurethane prepolymer.
The preparation method of the polyurethane prepolymer has the beneficial effects that: obtaining a first mixture after a first reaction between the first polyol and the isocyanate, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1; carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1; the silane coupling agent and the second mixture are subjected to a third reaction to obtain the polyurethane prepolymer, so that the content of free isocyanate monomers in the polyurethane prepolymer is reduced, the storage stability of the polyurethane prepolymer is improved, more amide groups are introduced into a molecular chain of the polyurethane prepolymer, the polarity of the molecular chain is improved, and the cohesive energy of the polyurethane prepolymer is increased finally. The preparation method of the polyurethane prepolymer solves the problem of high content of free isocyanate monomer in the polyurethane prepolymer.
Optionally, the temperature of the first reaction is 80 to 100 ℃, the time of the first reaction is 2 to 4 hours, the temperature of the second reaction is 80 to 100 ℃, and the time of the second reaction is 2 to 4 hours.
Optionally, the temperature of the third reaction is 50-60 ℃, the vacuum degree of the third reaction is-0.06-0.03 MPa, and the time of the third reaction is 20-40 min.
Optionally, the isocyanate is selected from any one of toluene diisocyanate, diphenylmethane-4, 4' -diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate.
Optionally, the first polyol is at least one selected from grease polyol, polyester polyol, polybutadiene polyol, polytetrahydrofuran polyol, polycarbonate polyol, polycaprolactone polyol, polylactic acid polyol and polyether polyol, and the second polyol is at least one selected from grease polyol, polyester polyol, polybutadiene polyol, polytetrahydrofuran polyol, polycarbonate polyol, polycaprolactone polyol, polylactic acid polyol and polyether polyol.
Optionally, the silane coupling agent contains a group that can react with-NCO.
Optionally, the group reactive with-NCO includes-NH 2 Any one of, -NH and-SH.
Optionally, the silane coupling agent is selected from any one of KH550, A-189 and Dynasylan 1124.
Optionally, the second mixture comprises a second prepolymer, and the weight percentage of the silane coupling agent in the second prepolymer is 0.1-1%.
The invention also aims to provide a polyurethane prepolymer, which is prepared by the preparation method of the polyurethane prepolymer.
The polyurethane prepolymer disclosed by the invention has the beneficial effects that: the polyurethane prepolymer is prepared by the preparation method of the polyurethane prepolymer, so that the content of free isocyanate monomers in the polyurethane prepolymer is reduced, the storage stability of the polyurethane prepolymer is improved, more amide groups are introduced into a molecular chain of the polyurethane prepolymer, the polarity of the molecular chain is improved, and the cohesive energy of the polyurethane prepolymer is increased finally. The polyurethane prepolymer solves the problem of high content of free isocyanate monomer in the polyurethane prepolymer.
The invention has the beneficial effects that: the content of free isocyanate monomer in the polyurethane prepolymer is lower than 1%, the health hazard to direct users is reduced to a low point, and the cost expenditure of enterprises in the aspect of EHS is saved; the content of free isocyanate monomers in the polyurethane prepolymer is reduced, the storage stability of the polyurethane prepolymer can be improved, and the isocyanate monomers can be subjected to self-polymerization or polyurea reaction with the polyurethane prepolymer in the presence of a small amount of free isocyanate monomers under certain conditions, so that the viscosity of the polyurethane prepolymer can be quickly increased in a short time; the introduction of hard and soft segments into the molecular chain of the polyurethane prepolymer at a microscale is favorable for improving the performance of products, and more amide groups are introduced into the molecular chain, so that the polarity of the molecular chain is improved, the cohesive energy of the polyurethane prepolymer is increased, and the mechanical property and the adhesion capacity to polar substrates of the products obtained from the polyurethane prepolymer are improved; the preparation method of the polyurethane prepolymer disclosed by the invention does not need to additionally input expensive film evaporation equipment, and can be implemented by using the existing reaction kettle for preparing the polyurethane prepolymer.
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Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but 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. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the word "comprising" and similar words are intended to mean that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.
In the embodiment of the invention, the preparation method of the polyurethane prepolymer comprises the following steps:
s0: providing a first polyol, a second polyol, an isocyanate, and a silane coupling agent;
s1: carrying out a first reaction on the first polyol and the isocyanate to obtain a first mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1;
s2: carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1;
s3: and carrying out a third reaction on the silane coupling agent and the second mixture to obtain the polyurethane prepolymer.
Specifically, a first mixture is obtained after the first polyol and the isocyanate are subjected to a first reaction, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1; carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1; the silane coupling agent and the second mixture are subjected to a third reaction to obtain the polyurethane prepolymer, so that the content of free isocyanate monomers in the polyurethane prepolymer is reduced, the storage stability of the polyurethane prepolymer is improved, more amide groups are introduced into a molecular chain of the polyurethane prepolymer, the polarity of the molecular chain is improved, and the cohesive energy of the polyurethane prepolymer is increased finally. The preparation method of the polyurethane prepolymer solves the problem of high content of free isocyanate monomer in the polyurethane prepolymer.
In some embodiments of the present invention, the first mixture comprises a first prepolymer and unreacted isocyanate, wherein the first prepolymer has a general formula of NCO-R-NHCO-R 1 -CONH-R-NCO。
In some embodiments of the present invention, the second mixture comprises a second prepolymer, a side reaction product and unreacted isocyanate, wherein the second prepolymer has a general formula of NCO-R-NHCO-R 1 -CONH-R-NHCO-R 2 -OCNH-R-NHCO-R 1 -OCNH-R-NCO, said side reaction product having the formula NCO-R 2 -NCO。
In some embodiments of the present invention, a third reaction of the unreacted isocyanate with the silane coupling agent occurs.
In some embodiments of the present invention, the unreacted isocyanate refers to isocyanate in which the — NCO groups are not linked to other groups.
In some embodiments of the invention, the molar ratio of the isocyanate group in the isocyanate to the hydroxyl group in the second polyol is (1.5-2): 1, so that the molecular weight of the polyurethane prepolymer is moderate, and more polar urethane bonds are formed in a chain segment of the polyurethane prepolymer, thereby improving the adhesion of the polyurethane prepolymer to polar base materials and the cohesive strength of the polyurethane prepolymer.
In some embodiments of the invention, the molar ratio of the isocyanate in the isocyanate to the hydroxyl in the second polyol is (2-3): 1, so that the molecular weight of the polyurethane prepolymer is small, and the viscosity of the polyurethane prepolymer is moderate and the stability is good.
If the molar ratio of isocyanate in isocyanate to hydroxyl in the second polyol is less than 1.5, the formed polyurethane prepolymer has a large molecular weight and high viscosity, which is not beneficial to the subsequent application of the polyurethane prepolymer, and the viscosity stability of the polyurethane prepolymer is deteriorated.
If the molar ratio of the isocyanic acid radical in the isocyanate to the hydroxyl in the second polyol is larger than 3, the formed polyurethane prepolymer has good stability, but the content of the monomer in the polyurethane prepolymer is relatively high, so that the performance of the polyurethane prepolymer is reduced, the strength and the cohesive strength of the polyurethane prepolymer are also reduced, and the adhesive force of the polyurethane prepolymer to a polar base material is weakened.
In some embodiments of the present invention, the molar ratio of isocyanate groups in the isocyanate to hydroxyl groups in the first polyol is 1.5.
In some embodiments of the present invention, the step of providing the first polyol, the second polyol, the isocyanate, and the silane coupling agent in step S0 comprises: dehydrating the first polyhydric alcohol and the second polyhydric alcohol for 1 to 5 hours at the temperature of between 100 and 140 ℃ and the vacuum degree of between-0.1 and-0.03 MPa.
In some embodiments of the present invention, the temperature of the first reaction is 80 to 100 ℃, the time of the first reaction is 2 to 4 hours, the temperature of the second reaction is 80 to 100 ℃, and the time of the second reaction is 2 to 4 hours.
In some embodiments of the present invention, the temperature of the third reaction is 50 to 60 ℃, the vacuum degree of the third reaction is-0.06 to-0.03 MPa, and the time of the third reaction is 20 to 40min.
In some embodiments of the present invention, the isocyanate is selected from any one of toluene diisocyanate, diphenylmethane-4, 4' -diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. In some embodiments, the toluene diisocyanate is abbreviated as TDI, the diphenylmethane-4, 4' -diisocyanate is abbreviated as MDI, the isophorone diisocyanate is abbreviated as IPDI, and the hexamethylene diisocyanate is abbreviated as HDI.
In some embodiments of the present invention, the isocyanate has the formula NCO-R-NCO, wherein R is selected from the group consisting of 2,4-TDI, 2,6-TDI, 4'-MDI, 2,4-MDI, 2' -MDI, IPDI and HDI.
In some embodiments of the invention, the 2,4-TDI is of the formula
The structural formula of the 2,6-TDI is shown as
The structural formula of the 4,4' -MDI is shown in the specification
The structural formula of the 2,4-MDI is shown in the specification
The structural formula of the 2,2' -MDI is shown in the specification
The structural formula of the IPDI is
The structural formula of the HDI is
In some embodiments of the present invention, the first polyol is selected from at least one of an oil polyol, a polyester polyol, a polybutadiene polyol, a polytetrahydrofuran polyol, a polycarbonate polyol, a polycaprolactone polyol, a polylactic acid polyol and a polyether polyol, and the second polyol is selected from at least one of an oil polyol, a polyester polyol, a polybutadiene polyol, a polytetrahydrofuran polyol, a polycarbonate polyol, a polycaprolactone polyol, a polylactic acid polyol and a polyether polyol.
In some embodiments of the invention, the oil polyol comprises at least one of a castor oil polyol, a soybean oil polyol, a palm oil polyol, a rapeseed oil polyol, a cottonseed oil polyol, a peanut oil polyol, and a sunflower oil polyol.
In some embodiments of the invention, the first polyol has a number average molecular weight of 200 to 6000; the number average molecular weight of the second polyol is 200-6000. In some embodiments, the first polyol has a number average molecular weight of 400 to 4000; the number average molecular weight of the second polyhydric alcohol is 400 to 4000. In some more specific embodiments, the first polyol has a number average molecular weight of 400 to 2000; the number average molecular weight of the second polyol is 400 to 2000.
In some embodiments of the invention, the first polyol has the general formula HO-R 1 -OH, wherein R 1 Selected from the group consisting of polyether, polyester, polytetrahydrofuran, polybutadiene, polycarbonate and polycaprolactone.
In some embodiments of the invention, the second polyol has the general formula HO-R 2 -OH, wherein R 2 Selected from the group consisting of polyether, polyester, polytetrahydrofuran, polybutadiene, polycarbonate and polycaprolactone types.
In some embodiments of the present invention, the polyether type has the formula-O-, and the polyester type has the formula
The structural formula of the polytetrahydrofuran is shown in the specification
The polybutadiene type has a structural formula of
The structural formula of the polycarbonate type is shown in the specification
The structural formula of the polycaprolactone type is
In some embodiments of the invention, the silane coupling agent contains a group that is reactive with-NCO.
In some embodiments of the invention, the group reactive with-NCO comprises-NH 2 Any one of, -NH and-SH.
In some embodiments of the invention, the silane coupling agent is selected from any one of KH550, A-189, and Dynasylan 1124.
In some embodiments of the present invention, the silane coupling agent is selected from any one of KH550, derivatives of KH550, A-189, derivatives of A-189, dynasylan1124 and derivatives of Dynasylan 1124.
In some embodiments of the invention, the KH550 has a structural formula
The structural formula of A-189 is
The Dynasylan1124 has a structural formula of
In some embodiments of the present invention, the second mixture includes a second performed polymer, and the weight of the silane coupling agent accounts for 0.1 to 1% of the weight of the second performed polymer. In some embodiments, the weight of the silane coupling agent in the second prepolymer is any one of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% and 1%. Preferably, the weight percentage of the silane coupling agent in the second prepolymer is 0.1-0.5%. More preferably, the weight percentage of the silane coupling agent in the second prepolymer is 0.1-0.3%.
In some embodiments of the present invention, the determination of the reaction end point of the step S1 and the step S2 is determined by whether the NCO% test reaches ± 0.05% of a theoretical value.
In some embodiments of the invention, the principle of the NCO% test is: the isocyanate group reacts with the excessive di-n-butylamine to generate urea, and the excessive di-n-butylamine is titrated by hydrochloric acid to quantitatively calculate the content of the isocyanate.
In some more specific embodiments of the invention, the experimental procedure for the NCO% test: accurately weighing 1.00g of sample into a dry conical flask, adding 25mL of toluene to dissolve the sample, accurately adding 25mL of di-n-butylamine-toluene solution, fully oscillating after plugging and sealing, standing for 15min, then adding 100mL of isopropanol and 5 drops of bromocresol green indicator, titrating to the end point (turning yellow from blue) by using 0.1mol/L HCl standard solution, and simultaneously carrying out blank experiment.
In some more specific embodiments of the present invention, the formula for the% NCO calculation is:
w NCO /％＝(V 0 -V)×c×4.202/m
in the formula: v 0 -the volume of blank consumed HCl standard solution in ml;
v is the volume of HCl standard solution consumed by the sample, and the unit is ml;
c-concentration of HCl standard solution, unit is mol/L;
m represents the mass of the sample in g.
The embodiment of the invention relates to a polyurethane prepolymer, which is prepared by a preparation method of the polyurethane prepolymer.
Specifically, the polyurethane prepolymer is prepared by the preparation method of the polyurethane prepolymer, so that the content of free isocyanate monomers in the polyurethane prepolymer is reduced, the storage stability of the polyurethane prepolymer is improved, and more amide groups are introduced into a molecular chain of the polyurethane prepolymer, so that the polarity of the molecular chain is improved, and finally the cohesive energy of the polyurethane prepolymer is increased. The polyurethane prepolymer solves the problem of high content of free isocyanate monomer in the polyurethane prepolymer.
Example 1
300g of polyether polyol DL-400, 785.3g of polyether polyol DL-2000, 394.2g of pure MDI and 2.96g of Dynasylan1124 are respectively weighed, and the polyether polyol DL-400 and the polyether polyol DL-2000 are dehydrated for 2 hours at the temperature of 120 ℃ and the vacuum degree of-0.1 MPa;
adding polyether polyol DL-400 and pure MDI into a 2L three-neck flask, reacting for 4 hours at the temperature of 80 ℃, wherein the reaction end point is determined after the NCO% is tested to be 9.96 +/-0.05%, so as to obtain a first mixture, wherein the first mixture comprises a first prepolymer, the content of the first prepolymer is 694.2g, and the molar ratio of isocyanate in the pure MDI to hydroxyl in the polyether polyol DL-400 is 2.1;
adding polyether polyol DL-2000 into the first mixture, reacting for 2 hours at the temperature of 100 ℃, and obtaining a second mixture after testing that NCO% is 2.45% +/-0.05%, wherein the second mixture comprises a second prepolymer, the content of the second prepolymer is 1479.5g, and the molar ratio of isocyanato in pure MDI to hydroxyl in the polyether polyol DL-2000 is 2.1;
dynasylan1124 was added to the second mixture, and reacted at 50 ℃ and a vacuum of-0.05 MPa for 30min to obtain a polyurethane prepolymer, which was designated as sample 1.
Example 2
300g of polyether polyol DL-400, 916.2g of polyether polyol DL-2000, 394.2g of pure MDI and 2.96g of Dynasylan1124 are respectively weighed, and the polyether polyol DL-400 and the polyether polyol DL-2000 are dehydrated for 4 hours at the temperature of 100 ℃ and the vacuum degree of-0.085 MPa;
adding polyether polyol DL-400 and pure MDI into a 2L three-neck flask, reacting for 3.5h at the temperature of 90 ℃, wherein the reaction end point is determined after the NCO% is tested to be 9.96 +/-0.05%, so as to obtain a first mixture, wherein the first mixture comprises a first prepolymer, the content of the first prepolymer is 694.2g, and the molar ratio of isocyanate in the pure MDI to hydroxyl in the polyether polyol DL-400 is 2.1;
adding polyether polyol DL-2000 into the first mixture, reacting for 4 hours at the temperature of 80 ℃, and obtaining a second mixture after testing that NCO% is 1.91% +0.05%, wherein the second mixture comprises a second prepolymer, the content of the second prepolymer is 1610.4g, and the molar ratio of isocyanate in pure MDI to hydroxyl in polyether polyol DL-2000 is 1.8;
dynasylan1124 was added to the second mixture and reacted at 60 ℃ under a vacuum of-0.05 MPa for 40min to obtain a polyurethane prepolymer, which was designated as sample 2.
Example 3
300g of polyether polyol DL-400, 666.9g of polyether polyol DL-2000, 337.9g of pure MDI and 2.96g of Dynasylan1124 are respectively weighed, and the polyether polyol DL-400 and the polyether polyol DL-2000 are dehydrated for 5 hours at the temperature of 140 ℃ and the vacuum degree of-0.085 MPa;
adding polyether polyol DL-400 and pure MDI into a 2L three-neck flask, reacting for 3h at the temperature of 90 ℃, wherein the reaction end point is determined after the NCO% is tested to be 9.96 +/-0.05%, so as to obtain a first mixture, wherein the first mixture comprises a first prepolymer, the content of the first prepolymer is 637.9g, and the molar ratio of isocyanato in the pure MDI to hydroxyl in the polyether polyol DL-400 is 1.8;
adding polyether polyol DL-2000 into the first mixture, reacting for 3 hours at the temperature of 90 ℃, and obtaining a second mixture after testing that NCO% is 1.71% +0.05%, wherein the second mixture comprises a second prepolymer, the content of the second prepolymer is 1304.8g, and the molar ratio of isocyanato in pure MDI to hydroxyl in polyether polyol DL-2000 is 2.4;
dynasylan1124 was added to the second mixture and reacted at a temperature of 55 ℃ and a vacuum of-0.05 MPa for 40min to obtain a polyurethane prepolymer, which was designated as sample 3.
Comparative example
Respectively weighing 300g of polyether polyol DL-400, 700g of polyether polyol DL-2000 and 578.2g of pure MDI, dehydrating the polyether polyol DL-400 and the polyether polyol DL-2000 for 2h at the temperature of 120 ℃ and the vacuum degree of-0.1 MPa, wherein the molar ratio of isocyanic acid radicals in the pure MDI to hydroxyl radicals in the polyether polyol is 2.1;
adding polyether polyol DL-400, polyether polyol DL-2000 and pure MDI into a 2L three-neck flask, reacting for 4 hours at the temperature of 80 ℃, and obtaining a polyurethane prepolymer which is marked as a comparison sample after testing that the NCO% is 6.43 +/-0.05%.
Content measurement of free isocyanate monomer
The content of free isocyanate monomer in the polyurethane prepolymer is harmful to the health of direct users, and the specific standard is shown in table 1.
TABLE 1
| Content of free isocyanate monomer | Hazard information code |
| 5％～10％ | Xn,R36/37/38-R40-R42/43-R48/20 |
| 1％～5％ | Xn,R40-R42/43 |
| 0.1％～1％ | Xn,R42 |
| <0.1％ | Non-tag |
The european union REACH regulations limit the content of isocyanate monomers as shown in table 2.
TABLE 2
| Hazard information code | Hazard courseDegree of rotation |
| Xn | Is harmful to health |
| R20 | Inhalation is harmful |
| R36/37/38 | Has stimulating effect on eyes, respiratory system and skin |
| R40 | Has carcinogenic hazard |
| R42/43 | Can be used for sensitizing by inhalation and skin contact |
The isocyanate content of samples 1-3 and the comparative samples were measured using a gas chromatograph-mass spectrometer and the results are shown in Table 3.
TABLE 3
| Sample 1 | Sample 2 | Sample 3 | Comparative sample | |
| Content of isocyanate monomer | 0.8％ | 0.7 | 0.65 | 2％ |
As can be seen from the data in table 3, the content of isocyanate monomer in samples 1 to 4 is significantly reduced compared to the comparative sample, thereby indicating that the content of free isocyanate monomer can be reduced in the polyurethane prepolymer obtained by the preparation method of the polyurethane prepolymer of the present invention. The existence of a small amount of isocyanate monomer can generate self-polymerization or polyurea reaction with the prepolymer under certain conditions, so that the viscosity of the polyurethane prepolymer can be quickly increased in a short time.
And (3) testing the storage stability: the initial viscosities of samples 1-3 and the comparative sample were tested, and then the final viscosities of samples 1-3 and the comparative sample were tested after placing samples 1-3 and the comparative sample at 50 degrees celsius for one week, with the test results shown in table 4. Viscosity swing = (final viscosity-initial viscosity) ÷ initial viscosity × 100%. The test standards for initial and final viscosities are GB/T9751.1-2008.
TABLE 4
| Aging conditions | Sample 1 | Sample 2 | Sample 3 | Comparative sample |
| Initial viscosity/mPa.s | 8205 | 10020 | 12030 | 4315 |
| Final viscosity/mPa.s | 9530 | 13200 | 15900 | 8900 |
| Viscosity fluctuation/% | 16 | 32 | 32 | 106 |
As can be seen from the data in table 4, the storage stability of samples 1 to 3 is significantly improved compared to the comparative sample, which indicates that the stability of the polyurethane prepolymer obtained by the preparation method of the polyurethane prepolymer of the present invention can be improved.
Application of polyurethane prepolymer
Respectively reacting and curing samples 1-3 and a comparative sample with castor oil polyol to obtain thermosetting resins 1-3 and comparative resin, wherein the molar ratio of the isocyanic acid radical in the sample 1 to the hydroxyl in the castor oil polyol is 1, the molar ratio of the isocyanic acid radical in the sample 2 to the hydroxyl in the castor oil polyol is 1, the molar ratio of the isocyanic acid radical in the sample 3 to the hydroxyl in the castor oil polyol is 1, and the molar ratio of the isocyanic acid radical in the comparative sample to the hydroxyl in the castor oil polyol is 1. The tensile strength and elongation at break of the thermosetting resins 1 to 3 and the comparative resin were measured after curing the thermosetting resins 1 to 3 and the comparative resin at 23 ℃ and 50% ambient humidity for 7 days, respectively, and the results are shown in table 5.
TABLE 5
As can be seen from the data in table 5, the tensile strength of the thermosetting resins 1 to 3 obtained using samples 1 to 3 was significantly improved, and the elongation at break was significantly reduced, as compared to the comparative resin obtained using the comparative sample. The polyurethane prepolymer prepared by the preparation method can improve the tensile strength of the product and reduce the elongation at break of the product in the use process.
The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as can be conceived and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Where the claims recite a range of values, such ranges are intended to include all sub-ranges subsumed therein, and variations within the ranges are intended to be encompassed by the claims as appended hereto where possible.
Claims (10)
1. The preparation method of the polyurethane prepolymer is characterized by comprising the following steps:
s0: providing a first polyol, a second polyol, an isocyanate, and a silane coupling agent;
s1: carrying out a first reaction on the first polyol and the isocyanate to obtain a first mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the first polyol is (1.5-2.5): 1;
s2: carrying out a second reaction on the second polyol and the first mixture to obtain a second mixture, wherein the molar ratio of isocyanate in the isocyanate to hydroxyl in the second polyol is (1.5-3) to 1;
s3: and carrying out a third reaction on the silane coupling agent and the second mixture to obtain the polyurethane prepolymer.
2. The method of claim 1, wherein the temperature of the first reaction is 80-100 ℃, the time of the first reaction is 2-4 hours, the temperature of the second reaction is 80-100 ℃, and the time of the second reaction is 2-4 hours.
3. The method for preparing the polyurethane prepolymer according to claim 1, wherein the temperature of the third reaction is 50 to 60 ℃, the vacuum degree of the third reaction is-0.06 to-0.03 MPa, and the time of the third reaction is 20 to 40min.
4. The method of claim 1, wherein the isocyanate is any one selected from the group consisting of toluene diisocyanate, diphenylmethane-4, 4' -diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.
5. The method of preparing a polyurethane prepolymer according to claim 1, wherein the first polyol is at least one selected from the group consisting of oil polyols, polyester polyols, polybutadiene polyols, polytetrahydrofuran polyols, polycarbonate polyols, polycaprolactone polyols, polylactic acid polyols, and polyether polyols, and the second polyol is at least one selected from the group consisting of oil polyols, polyester polyols, polybutadiene polyols, polytetrahydrofuran polyols, polycarbonate polyols, polycaprolactone polyols, polylactic acid polyols, and polyether polyols.
6. The method of preparing a polyurethane prepolymer as defined in claim 1, wherein the silane coupling agent contains a group that reacts with-NCO.
7. According toThe method of preparing a polyurethane prepolymer of claim 6 wherein the group reactive with-NCO comprises-NH 2 Any one of-NH and-SH.
8. The method of preparing a polyurethane prepolymer according to claim 1, wherein the silane coupling agent is any one selected from the group consisting of KH550, a-189 and dynasyllan 1124.
9. The method for preparing the polyurethane prepolymer according to claim 1, wherein the second mixture comprises a second prepolymer, and the weight of the silane coupling agent is 0.1-1% of the weight of the second prepolymer.
10. A polyurethane prepolymer, which is obtained by the method for producing a polyurethane prepolymer according to any one of claims 1 to 9.
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| CN107406574A (en) * | 2015-03-12 | 2017-11-28 | 汉高股份有限及两合公司 | Ultralow monomer polyurethane |
| CN108084395A (en) * | 2017-12-27 | 2018-05-29 | 上海东大化学有限公司 | A kind of low modulus silicane-modified polyurethane resin material and preparation method thereof |
| CN111019112A (en) * | 2019-12-20 | 2020-04-17 | 上海东大化学有限公司 | Antibacterial silane modified polyether and preparation method thereof |
| CN115246918A (en) * | 2021-10-26 | 2022-10-28 | 佳化化学科技发展（上海）有限公司 | Silane modified polyurethane resin and preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107406574A (en) * | 2015-03-12 | 2017-11-28 | 汉高股份有限及两合公司 | Ultralow monomer polyurethane |
| CN108084395A (en) * | 2017-12-27 | 2018-05-29 | 上海东大化学有限公司 | A kind of low modulus silicane-modified polyurethane resin material and preparation method thereof |
| CN111019112A (en) * | 2019-12-20 | 2020-04-17 | 上海东大化学有限公司 | Antibacterial silane modified polyether and preparation method thereof |
| CN115246918A (en) * | 2021-10-26 | 2022-10-28 | 佳化化学科技发展（上海）有限公司 | Silane modified polyurethane resin and preparation method and application thereof |
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