CN-122011377-A - Non-isocyanate polyurethane and preparation method thereof

CN122011377ACN 122011377 ACN122011377 ACN 122011377ACN-122011377-A

Abstract

The prior art can not effectively and synchronously solve the defect of mechanical property while improving the reactivity. The invention provides a preparation method of non-isocyanate polyurethane, which comprises the steps of performing cycloaddition reaction on a compound containing two or more epoxy groups and carbon dioxide under the assistance of a catalyst to obtain a double five-membered ring carbonate oligomer, dissolving the double five-membered ring carbonate oligomer in a first solvent, performing halogenated reagent substitution reaction under the assistance of a free radical initiator to obtain halogenated double five-membered ring carbonate, dissolving the halogenated double five-membered ring carbonate in a second solvent and performing ring-opening polymerization reaction on diamine compound to obtain non-isocyanate polyurethane with a main chain containing lateral group halogen atoms, adding a double tertiary amine compound into the non-isocyanate polyurethane with the lateral group halogen atoms, and mixing and reacting to obtain the non-isocyanate polyurethane. Not only activates the polymerization reaction, but also serves as an anchor point for post-crosslinking, thereby overcoming two difficulties of reactivity and mechanical property.

Inventors

GU YUCONG
XU HUAJUN
LI BAO
SONG ZHIPENG
WANG SHUAIBING
TANG WEIFU

Assignees

杭州海维特未来科技有限公司
丽水海维特新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (10)

1. A preparation method of non-isocyanate polyurethane is characterized by comprising the steps of performing cycloaddition reaction on a compound containing two or more epoxy groups and carbon dioxide under the assistance of a catalyst to obtain a double five-membered ring carbonate oligomer, dissolving the double five-membered ring carbonate oligomer in a first solvent, performing halogenated reagent substitution reaction under the assistance of a free radical initiator to obtain halogenated double five-membered ring carbonate, dissolving the halogenated double five-membered ring carbonate in a second solvent and performing ring-opening polymerization reaction on diamine compound to obtain non-isocyanate polyurethane with a main chain containing lateral group halogen atoms, adding a double tertiary amine compound into the non-isocyanate polyurethane with the main chain containing lateral group halogen atoms, and mixing and reacting to obtain the non-isocyanate polyurethane.
2. The method according to claim 1, wherein the mixing reaction comprises a quaternization substitution reaction of the di-tertiary amine compound with a halogen atom on a side group on a main chain, wherein the di-tertiary amine compound is used as a chemical crosslinking point to connect two molecular chains to construct a three-dimensional network structure, and the non-isocyanate polyurethane with enhanced mechanical properties is obtained through post-treatment.
3. The method according to claim 2, wherein the compound containing two or more epoxy groups is one or more of bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, glycerol triglycidyl ether, or epoxidized soybean oil, and the catalyst is one or more of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltriethylammonium chloride, phenyltrimethylammonium bromide, and bifunctional organoboron catalyst.
4. The method according to claim 3, wherein the cycloaddition reaction has a reaction pressure of 1.2 to 2MPa, a reaction temperature of 100 to 140 ℃, a reaction time of 6 to 12 hours, and a mass ratio of the compound containing two or more epoxy groups to the catalyst of 100 (1 to 3).
5. The method according to claim 4, wherein the halogenating agent is one or more of N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, the first solvent is one or more of carbon tetrachloride, benzotrifluoride, methylene chloride, chloroform, petroleum ether, and the free radical initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide.
6. The method of claim 1, wherein the temperature of the substitution reaction is 70-90 ℃, the time of the substitution reaction is 4-12 h, the substitution reaction is carried out under the protection of nitrogen, and the mass ratio of the bi-five-membered ring carbonate to the free radical initiator to the halogenated reagent is 100 (0.3-1.0): 30-50.
7. The method according to claim 6, wherein the diamine compound is one or more of ethylenediamine, 1, 3-propylenediamine, 1, 4-butylenediamine, 1, 6-hexamethylenediamine and isophoronediamine, the second solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, 1, 4-dioxane and methyl ethyl ketone, the mass ratio of the halogenated di-five-membered ring carbonate to the diamine compound is 100 (15-30), the temperature of the ring-opening polymerization reaction is 50-80 ℃, and the time of the ring-opening polymerization reaction is 2-3 h.
8. The process according to claim 7, wherein the bis-tertiary amine is N, N, N ', N' -tetramethyl ethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N ', one or more of N' -tetramethyl-1, 4-butanediamine, N, N, N ', N' -tetramethyl-1, 8-octanediamine, bis (3-dimethylaminopropyl) ether, and bis (2-diethylaminoethyl) ether.
9. The method according to claim 8, wherein the mass ratio of the non-isocyanate polyurethane containing the halogen atom of the side group to the di-tertiary amine compound is 100 (0.5-3), the temperature of the mixing reaction is 50-60 ℃, and the time of the mixing reaction is 3-6 hours.
10. A non-isocyanate polyurethane prepared by the method of any one of claims 1 to 9, wherein the non-isocyanate polyurethane has the structural formula: wherein R1 is an organic skeleton group, R1 is one or more of a polyol residue, a bisphenol residue and an epoxidized vegetable oil residue, R 2 is a divalent organic group, R 2 is a C2-C10 alkylene group, an alicyclic di-group or a polyether group, n is the number of repeating units, R 3 is a divalent organic group, R 3 is a C2-C10 alkylene group or a C4-C20 alkylene group containing an ether bond, Is cationic.

Description

Non-isocyanate polyurethane and preparation method thereof Technical Field The invention relates to the technical field of polyurethane materials, in particular to non-isocyanate polyurethane and a preparation method thereof. Background Polyurethane materials are widely used, but traditional synthesis relies on highly toxic isocyanate, and is extremely harmful to human bodies and the environment. Non-isocyanate polyurethanes (NIPUs) are mainly prepared by ring-opening reactions of polybasic cyclic carbonates with polyamines, and are of great interest because of their green environmental protection properties. However, the technical route has two major core problems, which severely restrict the industrial application of the five-membered ring carbonate, namely low reactivity, weak electrophilicity of the five-membered ring carbonate, low reaction rate with amines than the traditional isocyanate system, slow polymerization, insufficient mechanical property, relatively single structure of the traditional NIPU main chain, and lack of effective crosslinking network construction means. Compared with the traditional polyurethane capable of flexibly adjusting the hard segment, the soft segment and the crosslinking degree, the NIPU has the problems of low strength, small modulus, poor heat resistance and the like, and is difficult to meet the requirements of high-performance application scenes. In the prior art, although research is carried out on improving the reactivity by introducing electron withdrawing groups on cyclic carbonates, the modification is often only applied to the polymerization stage, and has limited contribution to improving the mechanical properties of the final polymer. In other words, the prior art cannot effectively and synchronously solve the problem of insufficient mechanical properties while improving the reactivity. How to realize the crossing type improvement of the mechanical property of the NIPU material on the basis of green synthesis becomes a technical problem to be solved in the field. Disclosure of Invention Aiming at the problem that the prior art cannot effectively and synchronously solve the problem of insufficient mechanical properties while improving the reactivity, the invention provides non-isocyanate polyurethane and a preparation method thereof. One of the technical schemes of the invention is that the two problems of low reaction activity and insufficient mechanical property in the synthesis of non-isocyanate polyurethane are solved by the molecular design of the 'dual functions' of halogen. Firstly, halogen atoms with strong electron attraction are introduced into the ring methylene of the five-membered ring carbonate, and the positive charges of carbonyl carbon are obviously enhanced by utilizing the induction effect of the halogen atoms, so that nucleophilic attack of diamine is easier to occur, the ring-opening polymerization rate is greatly accelerated, and the bottleneck that the traditional non-isocyanate polyurethane synthesis needs high-temperature long-time reaction is overcome. The two tertiary amine groups of the di-tertiary amine compound can react with halogens on different molecular chains in a nucleophilic substitution way to form stable quaternary ammonium salt cross-linking bonds, and the linear molecular chains are stitched into a three-dimensional network structure, so that the cross-linking density, tensile strength, modulus and heat resistance of the material are obviously improved. In short, the introduced halogen is not only an activating agent in the polymerization stage, but also a bridge in the crosslinking stage, and through the integrated design, the synchronous completion of the improvement of the reactivity and the enhancement of the mechanical property is realized, and the two complement each other, so that the non-isocyanate polyurethane material with the rapid curing characteristic and the excellent mechanical property is finally obtained. Specifically, S1, cycloaddition reaction is carried out on a compound containing two or more epoxy groups and carbon dioxide in a high-pressure reaction kettle under the assistance of a catalyst, and after the reaction is finished, unreacted CO 2 is slowly released, so as to obtain the double five-membered cyclic carbonate oligomer. Step S1 is schematically represented by R 1, which is an organic backbone group selected from the group consisting of a polyol residue, a bisphenol residue, an epoxidized vegetable oil residue, or any combination thereof: S2, dissolving the double five-membered ring carbonate obtained in the step S1 in a proper amount of solvent, carrying out a halogenated reagent substitution reaction under the assistance of a free radical initiator, and introducing halogen atoms into the five-membered ring carbonate ring to obtain halogenated double five-membered ring carbonate. Step S2 is schematically: and S3, dissolving the halogenated double five-membered ring carbonate obtained in the