摘要
以氢氧化锂为引发剂 ,采用环四硅氧烷作单体 ,二甲基甲酰胺作促进剂 ,分步加料 ,制备了一类新的三嵌段共聚有机硅氧烷 .分子中聚二苯基硅氧烷 (P)构成中间嵌段 ,两端连接聚二甲基 -甲基乙烯基硅氧烷 (M) ,形成MPM型嵌段共聚物 .聚二苯基硅氧烷 (P)的引入 ,是为增加分子间的引力 .分子中所含二苯基硅氧链节质量约占高分子总质量的 7% .为了便于硫化加工 ,适量的甲基-乙烯基硅氧链节分散在两个M嵌段中 ,其总的质量则分别占高分子总质量的 0 % ,0 .1% ,0 .2 % ,0 .4 %和 0 .6% .为便于比较硫化硅橡胶的力学性能 ,制备了相应的无规共聚物 .将所得全部共聚有机硅氧烷分别进行硫化 ,测定了某些力学性能发现 ,它们均优于相应的无规共聚物 .嵌段共聚物中甲基 -乙烯基硅氧链节的质量占高分子总质量的 0 .1%和 0 .2 % ,其硫化胶片的力学性能较高 .
Poly(dimethyl-methylvinyl-b-diphenyl-b-dimethyl-methylvinyl)silicone block copolymers (MPM) were prepared by means of step-adding, with using octamethylcyclotetrasiloxane (D 4) ,octaphenylcyclotetrasiloxane (P 4), tetramethyl-tetravinylcyclotetrasiloxane (V 4) as monomers, lithi- um hydroxide as an initiator, N, N-dimethylformamide (DMF) as a promotor. For convenience of vulcanization, methylvinylsiloxane units were put in M segments, and their contents are 0%, 0.1%, 0.2%, 0.4% and 0.6%, respectively. In order to contrast with the block copolymers the corresponding random copolymers were prepared at the same time. All the prepared polyorgano-siloxanes were vulcanized and the mechanical properties of the rubber plates obtained were measured. The results showed that the mechanical properties of the rubber plates of the block polyorgano-siloxanes are better than those of the rubber plates of the random polyorgano-siloxanes. When the contents of V 4 in the block polyorgano-siloxanes are between (0.1~0.2) %(wt), the mechanical properties of the rubber plates are better than those of the others.
出处
《山东大学学报(理学版)》
CAS
CSCD
北大核心
2002年第6期524-526,531,共4页
Journal of Shandong University(Natural Science)
关键词
嵌段聚有机硅氧烷
氢氧化锂
硅橡胶
力学性能
N
N-二甲基甲酰胺
block polyorgano-siloxanes
lithium hydroxide
silicone rubber
mechanical properties
N, N-dimethylformamide