摘要
以氢氧化锂为引发剂 ,二甲基甲酰胺为促进剂 ,采用分步投料法合成出聚二甲基 (甲基乙烯基 )硅氧烷—聚二甲基二苯基 (甲基乙烯基 )硅氧烷—聚二甲基 (甲基乙烯基 )硅氧烷三嵌段共聚物 ;研究了四甲基四乙烯基环四硅氧烷 (DVi4 )用量对嵌段共聚物的摩尔质量及所制硅橡胶物理机械性能的影响。结果表明 ,DVi4 用量对嵌段共聚物的摩尔质量影响不大 ,但对硅橡胶的物理机械性能影响很大。当DVi4 质量分数为 0 1%、 0 2 %时 ,硅橡胶的物理机械性能较好 ,拉伸强度可达 10 70MPa ,撕裂强度最大为 2 4 6 1kN/m ,拉伸永久变形为 2 %～ 4%。
s:The tri-block copolymer( ABA ) of polydimethyl-methylvinylsiloxane( A ) with polydimethyl-diphenyl-methylvinylsiloxane( B )was prepared by means of step-adding,with using lithium, hydroxide as anionic initiator,N,N-dimethylformamide(DMF)as a promotor.The effects of tetramethyltetravinylcyclosiloxane (D Vi 4)on the molecular weight of the copolymer and the physical-mechanical property of vulcanized rubber prepared from the silicone copolymer were studied.The results showed that the content of D Vi 4 had a little effect on the molecular weight and large effect on the physical-mechanical property.When the content of diphenyl silicone units was 7(wt)% and the contents of D Vi 4 were 0,0.1(wt)%,0.2(wt)%,0.4(wt)%,0.6(wt)%,the vulcanized rubber prepered from the silicone copolymer had good physical-machanical properties.The tensile strength,tear strength and tensile set were 10.70MPa,24 61 kN/m,2%～4%,respectively.
出处
《有机硅材料》
CAS
2001年第6期12-14,共3页
Silicone Material
