云点法研究丙烯腈共聚体系反应活性及其与热稳定性能的关联  

Studies on the Reactivity of AN Copolymerization Systems by Cloudy Point Experiments and the Thermal Stability of the Copolymers

作　　者：曾照坡[1] 肖茹[1] 吕永根[1] 

机构地区：[1]东华大学材料科学与工程学院纤维材料改性国家重点实验室,上海201620

出　　处：《高分子学报》2016年第6期775-782,共8页Acta Polymerica Sinica

基　　金：国家重点基础研究发展计划(973计划;项目号2011CB605602;2011CB605603)资助项目

摘　　要：采用滴定实验法分别测试了衣康酸(IA)、丙烯酰胺(AM)、丙烯酸甲酯(MA)与丙烯腈(AN)一系列单体组成比时的云点;采用红外光谱、示差扫描量热分析和热失重分析研究了共聚单体的选择对共聚物热稳定化反应的影响和机理及其与共聚体系反应活性的关联.结果显示,IA、AM或MA的引入有利于提高AN聚合体系的云点,不同共单体用量构成的云点迹线斜率可以比较共聚体系反应活性,并对AN共聚体系组成的优化选择具有普适性;而AN与IA较高的共聚反应活性使得P(AN/IA)聚合物热稳定性能好,氰基未环化指数、环化反应起始温度及表观活化能低,环化反应速率快,这可能由于IA分子结构含有2个羧基,引发活性点较多,可以在低温条件下引发氰基环化形成更多的梯形结构.The cloudy points of acrylonitrile（ AN） copolymerization with itaconic acid（ IA）,acrylamide（ AM）,methyl acrylate（ MA） based on a series of different monomer composition ratios were determined by titration experiments. The various comonomers＇ influence on the stabilization of reactions and the relevance to the reactivity of PAN copolymerization systems were characterized by combining the methods of FTIR,DSC and TGA. The results showed that the introduction of comonomer helped to improve the cloudy point of polymerization system and the slope of cloudy point versus comonomer content lines was suggested for comparing the reactivity of copolymerization systems and the suitability of various copolymerization systems for carbon fiber precursor. The higher reactivity of AN and IA copolymerization system resulted in a preferably thermal stability performance of P（ AN/IA） polymer with a lower CN fraction unreacted, the onset temperature,apparent activation energy and faster rate constant value of cyclization reaction,which was probably because the two carboxylic acid groups in the molecular structure and more priming activity points can initiate the ionic cyclization reaction,making PAN convert into more ladder structures at low temperatures.

关 键 词：丙烯腈 云点 衣康酸 热稳定化 

分 类 号：O632.62[理学—高分子化学]