【摘要】 采用现场 XRD(X射线衍射 )法对 PAN(聚丙烯腈 )长丝在低温热解过程中取向参数的变化进行了探索性的研究。实验结果表明 ,PAN纤维中的蕴晶对纤维轴有明显的择优取向。当热解温度升到 2 0 0℃时 ,纤维内部的大分子链发生解取向现象 ,从而导致纤维在热解过程中形成较大反应区域的交联结构。并且 ,随着热解温度的提高 ,纤维内部序态结构逐渐规整化。同时 ,还连续测定了 1 K和 1 2 K两种丝束试样在不同温度下的取向度 ,它们分别为78.89% ,78.72 % (室温 ) ;74 .4 4 % ,75.2 8% (2 0 0℃ ) ;79.1 7% ,78.4 4 % (2 50℃ )和 78.3 3 % ,77.3 3 % (2 70℃ )。更多还原

【Abstract】 The changes of the oriented parameter of PAN filament yarn during low temperature pyrolysis are investigated with in situ X ray diffraction method in this paper. The experimental results show that the quasi crystal in fiber have been preferred orientation relative to the fiber axis obviously. When the pyrolysis temperature rising to 200 ℃, the deoriented phenomenon of the macromolecular chains in fibre interior has been occured, the cross linking structure of larger reaction zones is formed. And the orderingstructure in fiber interior with increasing pyrolysis temperature regularizes gradually. Simultaneously, the degree of relative preferred orientation for the samples of two typical filament bundle of 1 K and 12 K at different temperature have been measured still continuously, and its are 78.89%,78.72%(room temp.); 74.44%,75.28%(200 ℃); 79.17%,78.44%(250 ℃); 78.33%,77.33%(270 ℃) respectively.更多还原