摘要
采用原位红外技术跟踪SBS热氧化过程,同时通过热分析动力学技术计算了SBS的氧化动力学反应参数。研究表明,160℃以下时,氮气氛围中的SBS无降解断链现象发生。在氧气氛围下,SBS中的PB段发生热氧化降解及无规则断链。在300℃以下时,SBS中的PS段抗氧性能优异,无氧化发生;PB段中双键旁的α氢原子有很大活性,是氧化反应的进攻点,其热氧化降解同时存在解聚和无规断链,自动氧化反应是SBS热氧老化的主要特征,反应机理为自由链式,反应过程包括链引发、链增长和链终止,反应经过初始自由基的诱导期后,SBS迅速被氧化并发生严重降解。
The thermal oxidation process of SBS is tracked by in-situ FTIR ; meanwhile, the reaction parameters of SBS oxi- dation kinetics are calculated by thermal analysis kinetic. The results show that there is no chain scission and degradation occurred in nitrogen atmosphere below 160℃ ; while, in oxygen atmosphere, thermal oxidative degradation and random chain scission occur in PB segment of SBS; PS segment of SBS has excellent anti-oxidation performance and it can＇ t be oxi- dized when temperature is below 300℃. The α-H beside the double-bond has great activity, which is easy to be oxidized. The results also show that both of chain scission and de-polymerization occur in the thermal oxidation reaction. Auto-oxida- tion is the main feature of SBS thermal aging oxidation process. The mechanism of the reaction is freely-chained reaction, which includes chain initiation, chain growth and chain termination. After the reaction experiences the induction period of initial free radical, SBS is oxidized rapidly and degraded severely.
出处
《重庆交通大学学报（自然科学版）》
CAS
北大核心
2010年第1期157-161,共5页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家高技术研究发展计划项目(863计划)(2003AA333020)
关键词
SBS热氧化
原位红外
热分析动力学
自动氧化
thermal oxidation of SBS
in-situ I^FIR
thermal analysis kinetics
auto-oxidation
