用DSC研究选择聚丙烯腈原丝的共聚单体

DSC study on the effect of co-monomers on the properties of PAN precursors

本文主要利用差示扫描量热分析（DSC）研究了聚丙烯腈的共聚物及其原丝的热性能，研究结果发现国产原丝具有相似的放热单峰，而日本某公司的原丝具有两个峰，分峰使聚丙烯腈原丝放热峰宽化，避免了在预氧化、碳化时放热集中产生熔化、断丝现象。聚丙烯腈原丝的纺丝、溶解、氨改性等加工过程不能明显改变其放热峰的形状，而共聚单体的种类和组成配比才是最重要的因素，通过适当的共聚单体选择、配比设计可以制得具有与日本原丝放热峰相似的聚丙烯腈聚合物或原丝。

This paper was mainly concentrated on the thermal properties of PAN precursors with different varieties and composition of co-monomers, which was characterized by the use of differential scanning calorimetry (DSC). Some domestic PAN precursors have only one exothermic peak as a result of having similar comonomers, but for that from Japan, there are two separated peaks, which makes the exothermic reaction temperature of PAN precursors wider, other than one sharply concentrated temperature zone, and a separated peak will alleviate the exothermic reaction and result in reduced entropic relaxation of the molecules, maybe can avoid to some extent fusion and breaking of fibers owing to overheating resulted from sharp heat producing reaction. The process of spinning, dissolving,drawing,etc. Could hardly influence the shape of DSC exothermic peaks, but the type and quantities of comonomers are the most important effect. In addition, a adequate selection of comonomers and their optimum composition, e.g. AN/FAMS/IA=97/2.2/0.8 (w/w/w), could obtain similar one to the DSC peak of abroad PAN precursors for carbon fibers.