自粘接聚碳酸酯液体硅橡胶的研究

Research on Liquid Silicone Rubber of Self-adhesive Polycarbonate

以八甲基环四硅氧烷、含氢四环体、偶联剂等为原料合成有机硅增粘剂。研究了增粘剂的用量对加成型液体硅橡胶物理机械性能、与聚碳酸酯(PC)自粘接性能和动态流变行为的影响。结果表明,增粘剂含有的Si—H和Si—Vi基团通过参与形成交联反应,能对胶料的物理机械性造成显著影响;同时,增粘剂所含羰基、烷氧基和环氧基等活性基团可促使胶料与PC基材发生自粘接反应并形成100%内聚破坏的可靠粘接;当增粘剂用量为1.5%时,胶料的拉伸强度为6.7 MPa,与PC自粘接的拉伸剪切强度可达2.3MPa,且达到100%内聚破坏。增粘剂的加入会显著影响胶料的流变行为,添加有增粘剂的胶料表现出良好的加工性能,在大幅应变范围内,体系的线性黏弹区随着增粘剂用量的增加而明显缩短,并呈现典型的"Payne效应";频率扫描的结果则表明:添加有增粘剂的胶料表现出良好的加工性能,可采用点胶、泵体注射、挤出、喷涂等工艺硫化成型。

A new silicone adhesive promoter was synthesized by octamethylcy-clotetrasiloxane( D_4),hydromethylcy-closiloxanes( D_4~H) and the coupling agents as the raw materials. We researched adhesive promoting content effect on mechanical properties,self-adhesive Polycarbonate( PC) and rheological properties on addition type liquid silicone rubber( LSR). Results showed that the functional groups Si—H and Si—Vi of adhesive,which participated in crosslinking reaction,had significant effect on mechanical properties and self-adhesive PC,when the appropriate dosage of adhesive promoter was 1. 5%,tensile strength of LSR was 6. 7MPa,tensile lap-shear strength of LSR was 2. 3MPa and reached 100% cohesive failure. Adhesive promoting had a significant influence on LSR rheological properties. The linear viscoelastic range( LVR) was significantly shortened in wide-range strain with the increase of the amount of adhesive promoting,which presented typical 'Payne effect',Frequency sweep results showed that adhesive promoting adding to LSR characterized by good processability,which can be used in the process of vulcanization,such as dispensing,injection,extrusion and spraying.