【摘要】 以羟基封端的二甲基甲基乙烯基(硅氧烷与聚硅氧烷)(C=C—PDMS—OH)为接枝主链,将单氢化端基二甲基硅氧烷(H-PDMS)作为接枝支链,通过卡斯特催化剂催化二者间的硅氢化反应形成具有瓶刷结构的柔性主链(Brush PDMS-OH)。再通过三甲氧基硼氧六环(TMOB)的动态交联和异佛尔酮二异氰酸酯扩链剂(IPDI)的稳态化学交联,制备主链带有支化链的冲击硬化材料(Brush Impact Hardening Polymer,B-IHP)。通过核磁共振波谱仪(NMR)、傅里叶变换红外光谱仪(FTIR)和流变仪等测试手段对材料结构和性能进行表征。结果表明,B-IHP具有良好的机械性能和冲击硬化性能,拉伸强度达到9. 8 MPa,冲击硬化值达到3500以上。B-IHP具有良好的自愈合性能,愈合效率可达95%以上,愈合时间仅为6 h。该柔性主链的支化结构可以明显降低主链发生链缠结的相对分子质量阈值,提升材料的冲击硬化性能和自愈合能力。更多还原

【Abstract】 Hydroxyl-terminated dimethylmethylvinyl( siloxane and polysiloxane)( CCPDMSOH) was used as the graft branched chain to form a flexible main chain( Brush PDMS-OH) with bottle brushes by hydrogenation of H-PDMS with the caster catalyst. Brush impact hardening polymer( B-IHP) with branched chains was prepared by dynamic cross-linking of trimethoxyboroxyhexacyclic( TMOB) and stable chemical cross-linking by isophorone diisocyanate extender( IPDI). The structure and properties of the material were characterized by nuclear magnetic resonance spectroscopy( NMR),Fourier transform infrared spectrometer( FTIR) and rheometer. The results show that B-IHP has good mechanical properties and impact hardening properties. Its tensile strength can reach 9. 8 MPa and impact hardening value can reach more than 3500.B-IHP has good self-healing performance,the healing efficiency can reach more than 95%,and the healing time is only 6 hours. The results show that the branched structure of flexible main chain can significantly reduce the relative molecular mass threshold of chain entanglement and improve the impact hardening and self-repairing ability of materials.更多还原