聚碳硅烷的高温高压合成与减压蒸馏  

Research on Synthesis of Polycarbosilane at High Temperature under High Pressure and Vacuum Distillation

作　　者：谢征芳[1] 程祥珍[1] 宋永才[1] 肖加余[1] 

机构地区：[1]国防科技大学航天与材料工程学院,湖南长沙410073

出　　处：《国防科技大学学报》2006年第2期39-43,共5页Journal of National University of Defense Technology

基　　金：湖南省自然科学基金资助项目(03JJY3070);国防科技重点实验室基金资助项目

摘　　要：采用高温高压法合成了聚碳硅烷(PCS),通过改变合成条件与减压蒸馏温度的方法对PCS分子量及其分布进行调控。研究表明,改变PCS的反应温度、反应时间,可以基本控制PCS的分子量及其分布范围。随着反应温度的提高,反应时间的延长,PCS的分子量逐渐增大,分子量分布变宽。当合成温度高于450℃,反应时间大于6h时,或温度高于460℃,反应时间大于4h时,PCS中出现高分子量部分。随着反应条件的强化,高分子量部分逐渐增加,甚至出现超高分子量部分。提高减压蒸馏温度,可以有效降低PCS的低分子含量,提高分子量,降低分散系数。减压蒸馏温度每提高50℃,PCS的低分子含量约降低8%,重均分子量约提高1000,分散系数平均降低约0.3。Polycarbosilanes （PCSs） are synthesized at high temperature under high pressure. Synthesis processing and vacuum distillation of PCS are investigated. The results show that the molecular weight and distribution of PCS can be roughly controlled by synthesis conditions. With the increase of the reaction temperature and time, the molecular weight grows with a broadened distribution, High molecular weight PCS appears when the reaction temperature is higher than 450℃ with reaction time over 6h, or 460℃ with 4h, respectively. Super-high molecular weight PCS can be obtained if the reaction temperature and time still keep on increasing. The low molecular weight PCS content decreases while the vacuum distillation temperature increases. The molecular weight of PCS, therefore, increases with a narrow distribution. When the vacuum distillation temperature increases 50℃ from 250℃, the low molecular weight content in PCS decreases about 8% with a drop of polydisperity index about 0.3 and a grow of average molecular weight of high molecular weight about 1000.

关 键 词：聚碳硅烷 合成 减压蒸馏 分子量及其分布 

分 类 号：TQ343[化学工程—化纤工业]