摘要
应用热分析(DSC-TGA)技术研究了丙烯腈含量对丁腈橡胶(NBR)热降解性能的影响,结合TGA-FT-IR分析了丙烯腈含量对热降解过程中NBR分子结构演变的影响。研究表明,NBR首先发生交联环化反应,然后发生断链降解反应。热交联反应主要发生在320℃-410℃,交联反应放出热量随丙烯腈含量增加而降低。NBR断链降解初期以腈基及其交联产物的断裂为主,后期以丁二烯基团及交联产物的断裂为主。在整个降解过程中,降解活化能随转化率增加先增加后减小,最大活化能出现在转化率15%-30%之间。低丙烯腈含量NBR中的-C≡N主要转变为-C=N,高丙烯腈含量的-C≡N基团除转化为-C=N外,还转化为烯基苯氮类物质、HCN和NH3。
The thermal degradation properties of nitrile -butadiene rubber（NBR）vulcanizates were sudied by I）SC TGA,and the changing process during degradation of NBR was analyzed by TGA-FT-IR. The results show thecross-linking and cyclization reaction of NBR occur in the initial degradation reaction, and then broken degradation reaction happens. The cross-linking reaction occurs at 320 12 - 410 12. With acrylonitrile content increasing, heats of cross-linking reaction decrease. At NBR fracture degradation stage, the nitrile and the cross-linked produms are first broken, then fracture of butadiene groups and cross-linked products occurs. Through the degradation process, the degradation activation energy firstly increases and then decreases with the conversion rate increasing. During degradation process, large number of low carbon chain compounds and small amount of benzene emerge. -C：-N group mainly changes into -C= N of NBR with low acrylonitrile （ACN）, and changes into be,;lzenenitrile, NH3 and HCN besides - C = N of NBR with high ACN.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2013年第3期103-106,110,共5页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(50902078)
关键词
丙烯腈
丁腈橡胶
热降解
热重红外联用
acrylonitrile
nitrile-butadiene rubber
thermal degradation
TGA-FT-IR
