摘要
空气湿度是影响聚丙烯腈(PAN)纤维预氧化过程中的重要环境因素之一,通过考察空气湿度对预氧化过程中纤维收缩率、预氧丝单丝直径、体密度及预氧丝力学性能的影响,结果表明空气湿度对预氧化过程有两种作用机制,一方面起塑化作用,有利于纤维在张力作用下的择优取向,有利于纤维单丝直径的细化,对双扩散有促进作用;另一方面则起钝化作用,阻碍大分子链段的构象调整,对预氧化反应有延迟作用,使预氧化反应以反应控制的方式进行,有利于均质预氧化纤维的形成。高温下空气相对湿度较之温度影响很小。
The effect of moisture in die oxidative stabilization of polyacrylonitrile fibers was investigated. The results showed that moisture plays two different roles in the stabilization process of acrylic precursors. Moisture was found performing as plasticizer under low temperature heat treatment. In the case of the high temperature treatment process, however, it was concluded that it is hydrogen bonds between H2O and oxygen-containing groups formed. in the oxidation reaction that prevent the occurrence of cyclization reactions. Both factors favored the diffusion of oxygen into the core of the PAN fibers and improved the properties of both oxidized fibers and final carbon fibers. However the moisture effect was retarded when temperature was high.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
2003年第1期25-30,共6页
New Carbon Materials
基金
中国科学院创新方向性项目(KGCX2 SW 204)
山西省自然科学青年科技研究基金(20021013)
太原市科技启明星计划
