聚丙烯腈纤维低温热解过程的剖析

用DSC、TGA、IR联合分析法研究了丙烯腈—衣康酸二元共聚纤维在空气中和氮气中从200℃～400℃的热解过程,探讨了其化学反应及从原丝到预氧化丝的结构演变。研究结果表明:在空气中的DSC曲线反映了在400℃以下的低温热解过程可分为三步,这三步反应使PAN二元共聚原丝在200～400℃范围内分散放热,形成热稳定的梯形结构。在氮气中的反应结果只能形成半共轭结构,由于没有氧的桥架作用,而始终没有分子间的交联反应,其产物也是不稳定的。

Dissection of Low Temperature Pyrolysis Process of Acrylic Fiber

The pyrolysis process of AN-Itaconic acid binary copolymerized fiber under air and Ns at 200 -400℃ is analyzed by DSC, TGA and IR combined method, the chemical reaction and the structural evolution from precusors to oxidized fiber are explored. The DSC curve under air reflects the pyro-liysis process below 400℃ and can be divided into 3 steps which causes the PAN binary copolymeri zed precusors to emit heat in a decentralized way from 200-4001 to form a heat stable ladder structure while the reaction in the N1 can only result in a half conjugated structure, there is no intermolecular reaction taking place through out, due to the lack of a oxygen bridge, thus the end product is unstable.