双交联网络有机硅弹性体的制备及其自修复性能研究  

Preparation and Self-healability of Silicone Elastomer with Dual-crosslinked Network

作　　者：刘珠 洪鹏[1] 向洪平[1] 黄梓英 罗青宏 杨先君 刘晓暄[1] Zhu Liu;Peng Hong;Hong-ping Xiang;Zi-ying Huang;Qing-hong Luo;Xian-jun Yang;Xiao-xuan Liu(Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter,School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006)

机构地区：[1]广东省功能软凝聚态物质重点实验室广东工业大学材料与能源学院,广州510006

出　　处：《高分子学报》2020年第6期656-669,I0006,共15页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51873043,21604014);广东省科技基金(基金号2015B010122005)资助项目。

摘　　要：首先通过水解缩合法制备出了不同巯基含量的无色透明巯基硅油(PDMS-SH),然后通过PDMS-SH与端乙烯基硅油的光诱导点击反应和羧基硅油与氨基硅油的热可逆动态离子交联构建出可逆/不可逆杂化双交联网络,制备出一种可快速UV固化及优异自修复性的有机硅透明弹性体.辐照强度为70 mW/cm^2,Darocur1173加入量为1.0 wt%,―SH/―Vi摩尔比为1.5/1时,巯基-烯点击聚合具有较高的凝胶率、转化率及聚合速率,且固化速率不受离子交联网络的影响.巯基-烯初网络形成后,进一步加热可促进离子网络的形成,提高弹性体力学性能.此外,动态离子交联网络在弹性体中均匀分布.增加离子交联网络可有效降低松弛活化能,有利于应力松弛及动态可逆性,同时热处理工艺有利于动态离子网络的移动及解离-重组过程,从而有利于双网络结构的形成及修复效率的提升.更重要的是,选用巯基硅油DE/15及离子交联网络含量仅15 wt%时,弹性体具有较优力学性能及自修复效率,多次修复后的修复效率仍可高达90%以上,同时快速固化的弹性体具有高达90%以上的可见光透光率.为基于可逆动态离子缔合诱导的快速固化自修复透明有机硅材料提供一种新型可行的制备方法.Silicone elastomer with self-healability can be developed by effectively constructing reversible dynamic bonds(i.e.,covalent and non-covalent).Due to the low bond energy of dynamic bonds,the mechanical properties of the silicone elastomers are generally poor.Besides,the self-healing silicone elastomers are usually not transparent due to their compatibility.To solve this problem,colourless and transparent sulfhydryl silicone oils(PDMS-SH)are firstly prepared by the hydrolysis-condensation reaction.Then a transparent silicone elastomer with fast UV curing rate and excellent self-healability can be achieved by the reversible-irreversible hybrid dualcrosslinked networks,constructed by the photo-induced click reaction of PDMS-SH and vinyl-terminated silicone oil(VPS),as well as the thermal reversible dynamic cross-linked network of carboxyl-and amino-modified silicone oil.If the irradiation intensity is 70 mW/cm2,the dosage of Darocur1173 is 1.0 wt%and the molar ratio of―SH/―Vi is 1.5/1,the thiol-ene photopolymerization has high gel content,conversion rate and polymerization rate,and will not be affected by ion cross-linked network.The formation of ionic crosslinking network and improvement of physical properties can be promoted via further heating.Moreover,the dynamic ionic crosslinking network is uniformly distributed in silicone elastomers.The increase of ion cross-linked network can effectively reduce the activation energy Ea,which is beneficial to the stress relaxation.Meanwhile,movement,dissociation and recombination of dynamic ion reversible network,as well as the formation of dual network structure can benefit from the heat treatment,so the improvement of healing efficiency will be more easily achieved.Importantly,the prepared silicone elastomer with a transmittance of 93%in visible light and healing efficiency over^90%after multiple healing cycles can be acquired,Therefore,a feasible approach is provided to impart reversible ionic association induced self-healing silicone materials.

关 键 词：巯基-烯点击光聚合 动态离子交联 杂化双网络 自修复有机硅弹性体 巯基硅油 

分 类 号：TQ334[化学工程—橡胶工业]