丁腈羟型聚氨酯弹性体的分子结构设计与电机械性能研究  

Molecular Structure Design and the Electromechanical Properties of Hydroxyl Terminal Butyl Nitrile Based Polyurethane Elastomer

作　　者：李德龙 康继航 田双飞 张洪 许诗琪 熊璐璐 崔旭东 王锋 黄炎昊 LI De-long;KANG Ji-hang;TIAN Shuang-fei;ZHANG Hong;XU Shi-qi;XIONG Lu-lu;CUI Xu-dong;WANG Feng;HUANG Yan-hao(College of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China)

机构地区：[1]重庆交通大学材料科学与工程学院,重庆400074 [2]中国工程物理研究院化工材料研究所,绵阳621900

出　　处：《高分子通报》2023年第4期481-494,共14页Polymer Bulletin

基　　金：重庆市科学技术局面上基金(cstc2021jcyj-msxmX0697)。

摘　　要：本文对端羟基聚丁二烯丙烯腈液态橡胶(丁腈羟,HTBN)进行端基化改性,合成带不同光活性端官能团的遥爪型丁腈羟(HTBN)预聚物,并最终通过光固化制备了不同分子链结构的丁腈羟型聚氨酯(BNPU)介电弹性体。研究表明,随着前驱体HTBN分子链长度的增加,固化交联后BNPU弹性体的线性链缠结网络密度增加,使得弹性体的模量(Y)和断裂伸长率(EB)分别最高增加到1.89 MPa与112.26%,同时使弹性体的玻璃化转变温度(Tg)降低。根据活性封端基团的不同,采用季戊四醇三丙烯酸酯(PETA)封端的HTBN预聚物,光固化后的BNPU弹性体内部形成较大体积位阻的局部交联区域,可使BNPU弹性体的Tg升高,热分解速率降低,同时相分离导致的界面极化增强,从而进一步提升弹性体介电性能:使BNPU弹性体样品在103Hz频率下介电常数(ε′)最高达到807,介电损耗保持在1以下。最终局部大位阻交联结构和一定量的氰基结构可协同赋予BNPU弹性体优异的综合电机械性能,克服了纯聚氨酯和高交联度丁腈橡胶模量大、易击穿的问题。In this work, the hydroxyl-terminated polybutadiene acrylonitrile liquid rubber(HTBN) was modified and blocked different photoactive end functional groups to prepare photoreactive telechelic polybutadiene acrylonitrile oligomers. After compounding with active small molecule and photoinitiator, as well as UV-light curing, polybutadiene acrylonitrile-based polyurethane(BNPU) dielectric elastomers with different molecular chain structures were fabricated. The results showed that with the increase of the molecular chain length in the HTBN precursor, the entanglement network density of the cured BNPU elastomers increased, further to provide a high Young’s modulus(Y) of utmost 1.89 MPa and a large elongation at break(EB) of 112.26% to the elastomer, respectively. The long molecular chain between crosslinking points can also reduce the glass transition temperature(Tg) of the elastomers. The BNPU elastomer which was cured from HTBN oligomer with pentaerythritol triacrylate(PETA) end-blocked can form partial cross-linking domains with large volume steric hindrance, endowing the BNPU elastomers with increased Tg, decreased thermal decomposition velocity and enhanced interfacial polarization between separated microphase. As a result, the dielectric properties of the BNPU elastomers with partial cross-linking regions were improved. For instance, the dielectric constant(ε′) of BNPU elastomer sample reached a maximum value of 807 under 10~3 Hz, and its dielectric loss(tanδ) can be maintained below 1. One can make a conclusion that the synergistic effect between partial cross-linking domains with large volume hindrance and cyan side groups can guarantee the BNPU elastomer an excellent comprehensive electromechanical property, proposing a solution to the issues of high modulus and low breakdown strength for pure polyurethane and highly cross-linked nitrile rubber.

关 键 词：丁腈羟 聚氨酯弹性体 分子结构 局部交联 介电性能 

分 类 号：TQ334[化学工程—橡胶工业]