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CN-118772369-B - Self-repairing polyurethane elastomer with bicontinuous phase structure and preparation method thereof

CN118772369BCN 118772369 BCN118772369 BCN 118772369BCN-118772369-B

Abstract

The invention discloses a self-repairing polyurethane elastomer with a bicontinuous phase structure and a preparation method thereof. The structural formula of the self-repairing polyurethane elastomer is as follows The catalyst is synthesized by one step with dibutyl tin dilaurate as catalyst, wherein the molar ratio of the dimethyl silicone polymer blocked by amino, isophorone diisocyanate and 5- (2-hydroxyethyl) -6-methyl-2-amino uracil is 1:1.1-1.5:0.1-0.5. The self-repairing polyurethane elastomer has a bicontinuous network structure, high elasticity, excellent fatigue resistance and good thermal stability.

Inventors

  • XU JIANHUA
  • LIU TONG
  • FU JIAJUN

Assignees

  • 南京理工大学

Dates

Publication Date
20260505
Application Date
20230406

Claims (8)

  1. 1. The self-repairing polyurethane elastomer with the bicontinuous phase structure is characterized by comprising the following structural formula: ,n≥22。
  2. 2. the method for preparing the self-repairing polyurethane elastomer with the bicontinuous phase structure according to claim 1, which is characterized by comprising the following specific steps: according to the molar ratio of 1:1.1-1.5:0.1-0.5 of the amino-terminated polydimethylsiloxane, isophorone diisocyanate and 5- (2-hydroxyethyl) -6-methyl-2-amino uracil, dissolving 5- (2-hydroxyethyl) -6-methyl-2-amino uracil powder, the amino-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate in N, N-dimethylformamide, carrying out reflux reaction under 70+/-10 ℃ while stirring in a nitrogen atmosphere, and cooling to room temperature after the reaction is finished to obtain the self-repairing polyurethane elastomer material.
  3. 3. The preparation method according to claim 2, wherein the 5- (2-hydroxyethyl) -6-methyl-2-aminouracil is prepared by reflux-reacting 2-acetylbutyrolactone, triethylamine and guanidine carbonate in ethanol for 4-6 hours, obtaining yellow powder solid by suction filtration after the reaction, further washing with ethanol and drying at 60 ℃ for 12-24 hours, obtaining white 5- (2-hydroxyethyl) -6-methyl-2-aminouracil powder.
  4. 4. The method of claim 2, wherein the amino-terminated polydimethylsiloxane has a number average molecular weight of 3000.
  5. 5. The process of claim 2 wherein the molar ratio of amino-terminated polydimethylsiloxane, isophorone diisocyanate, 5- (2-hydroxyethyl) -6-methyl-2-aminouracil is 1:1.3:0.3.
  6. 6. The preparation method according to claim 2, wherein the reflux reaction time is 12-18 h.
  7. 7. The method according to claim 2, wherein the concentration of the amino-terminated polydimethylsiloxane in the reaction system is 30 wt%.
  8. 8. The preparation method according to claim 2, wherein the mass of dibutyltin dilaurate is 1% of the mass of isophorone diisocyanate.

Description

Self-repairing polyurethane elastomer with bicontinuous phase structure and preparation method thereof Technical Field The invention belongs to the field of high polymer materials, and relates to a self-repairing polyurethane elastomer with a bicontinuous phase structure and a preparation method thereof. Background From ancient times, humans never stopped exploring and learning natural organisms, and therefore many biomimetic materials have been invented, which play a vital role in the progress of human society. For large biological systems, the most attractive is the self-healing ability of itself. In 2001 White published a report on self-healing epoxy resins [ Nature,2001,409,794-797] in the Nature journal, from which the research on self-healing polymeric materials was trended. With intensive research on dynamic chemistry (supramolecular chemistry and dynamic covalent bonding) of components, scientific researchers have been increasingly researched for self-repairing materials with different moduli (different hardness) in order to meet the practical application scene. For flexible (low modulus) polymer materials, they have been widely used in flexible electronic devices because of their excellent extensibility and bendability. However, the flexible electronic device is extremely vulnerable to damage in a daily use environment, and thus it is very necessary to develop a flexible electronic device having a self-repairing function. Based on the above reports, the university of stanford Bao Zhenan teaches the development of a self-healing polyurethane elastomer by layered hydrogen bonding [ adv. Mater.,2018,30,1706846] made from amino-terminated polydimethylsiloxane synthesized with 4,4' -methylenebis (phenylisocyanate), and isophorone diisocyanate, which recovered 78% mechanical properties at room temperature for 48 hours. In addition, the material has high damage resistance and crack propagation resistance, but the performance gradually decreases in the repeated use process, and in addition, the elastomer has no excellent thermodynamic stability. Crack propagation resistance is not sufficient to evaluate in only a single stretch, and it is well known that flexible electronic devices tend to bend, stretch thousands of times during actual use, and that cracks are extremely prone to propagate through the entire material during extremely high frequency reciprocation, which makes the material completely useless yet to repair. Therefore, for flexible electronic devices, it is urgent to develop a room temperature fatigue-resistant flexible self-repairing material with thermal stability. Disclosure of Invention The invention aims to provide a self-repairing polyurethane elastomer with a bicontinuous phase structure and a preparation method thereof. The technical scheme for realizing the purpose of the invention is as follows: The self-repairing polyurethane elastomer with a bicontinuous phase structure is synthesized in one step by using amino-terminated polydimethylsiloxane (NH 2-PDMS-NH2), isophorone diisocyanate (IPDI) and 5- (2-hydroxyethyl) -6-methyl-2-amino uracil with a molar ratio of 1:1.1-1.5:0.1-0.5, and the structural formula of the self-repairing polyurethane elastomer is as follows: n≥22。 The preparation method of the self-repairing polyurethane elastomer with the bicontinuous phase structure comprises the following specific steps: According to the molar ratio of 1:1.1-1.5:0.1-0.5 of the amino-terminated polydimethylsiloxane, isophorone diisocyanate and 5- (2-hydroxyethyl) -6-methyl-2-amino uracil, dissolving 5- (2-hydroxyethyl) -6-methyl-2-amino uracil powder, the amino-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate in N, N-dimethylformamide, carrying out reflux reaction under 70+/-10 ℃ while stirring in a nitrogen atmosphere, and cooling to room temperature after the reaction is finished to obtain the self-repairing polyurethane elastomer material. Preferably, the 5- (2-hydroxyethyl) -6-methyl-2-aminouracil is prepared by reflux-reacting 2-acetylbutyrolactone, triethylamine and guanidine carbonate in ethanol for 4-6 hours, obtaining a yellow powder solid by suction filtration after the reaction, further washing with ethanol and drying at 60 ℃ for 12-24 hours to obtain white 5- (2-hydroxyethyl) -6-methyl-2-aminouracil powder. Preferably, the amino-terminated polydimethylsiloxane has a number average molecular weight of 3000. Preferably, the molar ratio of the amino-terminated polydimethylsiloxane, isophorone diisocyanate, 5- (2-hydroxyethyl) -6-methyl-2-aminouracil is 1:1.3:0.3. Preferably, the reflux reaction time is 12-18 h. Preferably, the concentration of the amino-terminated polydimethylsiloxane in the reaction system is 30wt%. Preferably, the mass of dibutyltin dilaurate is 1% of the mass of isophorone diisocyanate. Compared with the prior art, the invention has the following advantages: According to the invention, 5- (2-hydroxyethyl) -6-methyl-2-amino uracil i