PAN/DMSO溶液等温结晶行为的研究

Isothermal crystallization behavior of PAN/DMSO solution

利用广角X射线衍射(WAXD)的方法研究了聚丙烯腈/二甲基亚砜(PAN/DMSO)溶液的等温结晶行为。结果表明:溶液中PAN分子链以无规线团的形态存在;一定结晶温度下,PAN的结晶度随着时间的延长而增大,且前期结晶成核速率大于中后期晶粒生长速率;提高结晶温度,PAN结晶速率增加,结晶更为完善,结晶完成后,结晶度可达80.5%;PAN/DMSO溶液的等温结晶过程分为4个阶段,即无定形态、短程有序的螺旋构象、长程有序结构及完善的晶态结构。

The isothermal crystallization behavior of polyacrylonitrile/dimethyl sulfoxide （PAN/DMSO） solution was studied by wide angle X-ray diffraction analysis （WAXD）.The results showed that the molecular chain of PAN in the solution existed in random coil state; the crystallinity of PAN increased while prolonging the time at a specific crystallization temperature and the crystalline nucleation rate at the early stage was higher than the crystal growth rate at the medium and later stages of crystallization; the crystallization rate of PAN increased and the crystalline structure became more perfect while raising the crystallization temperature,and the crystallinity could be 80.5% as the crystallization finished.The isothermal crystallization of PAN/DMSO solution could be divided into four stages,namely,amorphous structure,short-range ordered helical conformation,long-range ordered structure and perfect crystalline structure.