基于动态肟-氨酯键的自愈合生物基水性聚氨酯的制备及性能

Preparation and properties of self-healing bio-based waterborne polyurethane based on dynamic oxime-amino ester bond

摘要:

首先以香草醛和盐酸羟胺为原料合成香草肟（VO），然后将VO作为醇扩链剂，以2,2-二羟甲基丙酸（DMPA）为亲水扩链剂，通过与聚四氢呋喃（PTMEG）、异佛尔酮二异氰酸酯（IPDI）的聚合反应，制备了阴离子型香草肟自修复水性聚氨酯（VO-SWPU），并制成VO-SWPU薄膜。采用FTIR、1HNMR对VO进行结构表征；通过DSC和TGA对VO-SWPU薄膜进行热性能测试；基于自愈合实验和拉伸测试，考察了异氰酸酯指数（R值）和n(PTMEG)/n(VO)对制备的VO-SWPU薄膜自愈合能力和力学性能的影响。结果表明，VO的加入对VO-SWPU薄膜热降解过程没有显著影响，所有样品的T5%（失重5%时的温度）均在210 ℃以上；R＝1.2，n(PTMEG)/n(VO)＝2.5制备的SWPU-1薄膜在45 ℃下修复40 min后划痕完全消失；n(PTMEG)/n(VO)＝2.5制备的SWPU-1薄膜和SWPU-3薄膜在60 ℃下愈合2 h后，自修复后的SWPU-1薄膜和SWPU-3薄膜的拉伸强度分别为13.23和19.12 MPa，自修复效率分别为96.5%和82.2%。

Abstract:

Firstly, vanillin oxime (VO) was synthesized from vanillin and hydroxylamine hydrochloride. Then anionic vanilla oxime self-repairing waterborne polyurethane (VO-SWPU) was prepared by polymerization with polytetrahydrofuran (PTMEG) and isophorone diisocyanate (IPDI) using VO as alcohol extender and 2-dimethylol propionic acid (DMPA) as hydrophilic extender. VO-SWPU film was prepared. The structure of VO was characterized by FTIR and 1HNMR, and the thermal properties of VO-SWPU films were tested by DSC and TGA. Based on self-healing experiments and tensile tests, the effects of isocyanate index (R) and n (PTMEG) / n (VO) on the self-healing ability and mechanical properties of VO-SWPU films were investigated. The results show that the addition of VO has no significant effect on the thermal degradation process of VO-SWPU thin films, and the T5% (temperature of weight loss 5%) of all samples is above 210C. The scratches of SWPU-1 films prepared by R=1.2 ,n(PTMEG) / n (VO) = 2.5 disappear completely after being repaired at 45 ℃ for 40 min. After the SWPU-1 film and SWPU-3 film prepared by n (PTMEG) / n (VO) = 2.5 healed at 60 ℃ for 2 h, the tensile strength of the self-repaired SWPU-1 film and SWPU-3 film was 13.23 and 19.12 MPa, respectively, and the self-repair efficiency was 96.5% and 82.2%, respectively.