硼改性硅橡胶自粘带的自融合效应

Self-fusion Effect of Boron Modified Silicone Rubber Self-adhesive Tape

为探究硅橡胶自粘带的自融合粘接机理,通过硼酸与一种甲基乙烯基硅橡胶反应,制备了可自融合粘接的硅橡胶自粘带。通过拉伸试验追踪硅橡胶自粘带界面间的粘接力随温度和保温时间的变化,对自融合效应进行了验证;借助红外光谱测试,提出了自融合效应的物理模型。结果表明:反应体系中的硼酸含量为2.5%时,制得的自粘带具有最大的初粘力。当硅橡胶具备“硅氧烷长链网络中穿插含硼硅氧烷短链段”的分子结构时,良好接触的两层硅橡胶界面能通过硼原子与氧原子的络合形成强于聚硅氧烷分子间内聚力的粘接。络合不能瞬间完成,界面所处的温度越高,络合过程所需的时间越短。在60℃下,可在12 h内达到最佳络合强度。

In order to discover the bonding mechanism of self-adhesive silicone rubber tape,we prepared a selfadhesive silicone rubber tape through the reaction of boric acid and methyl-vinyl silicone rubber.The variation of bonding force at interface of self-adhesive silicone rubber tape with temperature and soaking time was traced by tensile tests,and the self-fusion effect was verified.A physical model of self-fusion effect was proposed with the help of infrared spectrum test.The results show that when the content of boric acid in the reaction system is 2.5%,the self-adhesive tape has the highest initial bonding force.When silicone rubber has the molecular structure of short chain boron-containing siloxanes imbedded in long chain siloxane network,the well contacted silicone rubber interfaces can bond through complexation between boron and oxygen atoms in the boron-containing siloxanes,and the bonding force is stronger than the cohesion among polysiloxane molecules.The complexation can not complete instantly,and the higher the temperature of interface,the shorter the time of complexation.Under 60℃,the complexation strength can reach the optimum value within 12 hours.