摘要:
本文以DTA、TG、TPDR及本体含氧官能团测定、孔隙结构分析为实验手段,对六种粉末状、纤维状样品进行了研究。结果表明:样品组成不同导致了本体羧基数目不同,而羧基数目增加引起了比表面积下降。不同的样品其环化反应热效应各不相同,纯聚体环化时放热较为剧烈,引入羧基后放热现象减缓。随样品本体羧基数目增加或比表面积下降,环化反应活化能下降,反应易于进行。当PAN在空气气氛中进行环化反应时,各步骤发生的顺序为:氧化→氰基环化→热解脱氢,且三者互有交叠,样品特性只对前两者具有影响。
Abstract:
Six kinds of PAN samples are studied by DTA,TG,TPDR,determination of functional groups containing oxygen and analysis of pore texture. The results show that the difference of sample composition leads to the difference of carboxy number,and the increase of carboxy number leads to the decrease of special area. Heat effects of cycligation reaction for six samples are different and the pure polymer generates more heat than other samples. The heat generated by the reaction is decreased after the introduction of carboxy group. With increasing of carbory number of samples bulk or decreasing of special area,activation energy of cycligation reaction is decreased.When cycligation reaction for PAN happened in air,the various steps happen in following order; oxidation,cycligation of cyan-thermal decomposition and dehydrogenatien.