有机碱催化苯基硅橡胶的合成与阻尼性能研究

Study of the Organobase Catalyzed Synthesis of Diphenyl Silicone Rubbers and Their Damping Property

采用有机环三磷腈碱(CTPB)为催化剂,通过阴离子开环聚合制备了不同苯基含量的高分子量二苯基硅橡胶生胶,添加白炭黑及其他阻尼填料制备成硅橡胶,研究了苯基含量、白炭黑用量以及不同填料对硅橡胶阻尼性能的影响.结果表明,苯基含量提高,硅橡胶的阻尼损耗峰向高温移动,有效阻尼温域变宽.添加50份白炭黑的40 mol%苯基硅橡胶,兼具良好的力学性能与阻尼性能,有效阻尼温域可达113℃(-31~82℃).采用炭黑K90和石墨烯片替代传统白炭黑填料,有效阻尼温域可进一步拓宽至127℃(-27~100℃)和133℃(-33~100℃).

Diphenyl silicone raw rubbers were efficiently prepared by anionic ring-opening copolymerization of cyclosiloxanes using CTPB as catalyst.The vulcanized silicone rubbers with different diphenylsiloxane contents were then prepared for studies of damping and other properties.The results showed that the mechanical properties of silicone rubbers first increased and then decreased with the diphenylsiloxane contents increasing from 5 mol%to 50 mol%.Accordingly,the damping loss peak moved to high temperature when the glass transition temperature increased,affording the widened effective damping temperature range.Among which,the silicone rubber with 40 mol% diphenylsiloxane and 50 phr silica exhibited best balance in mechanical and damping properties,with tensile strength of 7.0 MPa and elongation at break of 376%.The effective damping temperature range of this silicone rubber reached 113℃(-31℃ to 82℃)with the maximum loss peak(tanδ_(max))of 0.7.In addition,replacing the traditional silica filler with carbon black K90 and graphene sheet further enhanced damping performance,affording tanδmax value of 1.2 and 0.7 and broad effective damping temperature range of 127℃(-27℃ to 100℃)and 133℃(-33℃ to 100℃),respectively.This paper provided a novel method for preparing high damping silicone rubbers with wide temperature range,which have great potential for the industrialized application.