PAN原丝至碳纤维缺陷的形成与遗传性

The Formation and Heredity of Defects from PAN Precursor to Carbon Fiber

利用扫描电镜(SEM)研究了聚丙烯腈(PAN)原丝至碳纤维结构形态转化过程中缺陷的形成与遗传。结果表明,PAN初生纤维、原丝、预氧化纤维和碳纤维的表面缺陷主要包括沟槽、横纹、粘丝、并丝、杂质、划伤和孔洞等。PAN初生纤维和原丝的内部缺陷主要是皮芯结构、芯部疏松和孔洞。皮芯结构由凝固浴中纤维的双扩散所导致,一直保留到原丝、预氧化纤维直至碳纤维中,可以通过调整凝固的工艺参数增大原丝皮层比例,提高芯部致密性;内部孔洞的形成与扩散和相分离速率有关,可以通过改善致密化和蒸汽拉伸工艺来减少孔洞和减小孔洞尺寸。预氧化纤维中的皮芯结构的形成归因于原丝的遗传和氧的不均匀扩散。

The formation and heredity of defects from PAN precursor to carbon fiber was systematically inestigated by means of scanning electron microscopy （SEM）. The result revealed that surface defects of fibers had transmissibility, such as grooves, scratches and holes, which could be greatly reduced through changing manufacture processes, parameters and equipment precision. Interior defects had close interrelationship, such as skin-core multilayer morphology, loose core and holes, which could be overcome by ad- justing coagulation process, the temperature and time of pre-oxidation process. It could be concluded that alleviating the defects, such as skin-core morphology, loose core and deliberately optimizing fiber structures were essential to obtain high strength carbon fibers.