论文部分内容阅读
采用湿法纺丝得到聚丙烯腈(PAN)初生纤维,干燥后得到PAN初生纤维样品。利用电阻法确定初生纤维的共晶温度;获得初生纤维的冻干曲线;通过压汞法对初生纤维孔结构进行表征,并对比考察了鼓风干燥、自然风干和冷冻干燥对样品截面形貌的影响。结果表明:初生纤维的共晶温度为-55℃;鼓风干燥会使样品收缩,纤维间发生粘连,原有形貌被破坏;自然风干使样品的截面积和周长分别收缩了20.66%、10.67%,形状系数变化率为3.52%。而冷冻干燥时样品的截面积和周长仅收缩了1.21%、1.15%,形状系数变化率为1.13%。冷冻干燥有效地保留了PAN初生纤维的固有原始结构,可用于制备各种分析的样品。
Polyacrylonitrile (PAN) primary fibers were obtained by wet spinning, and PAN primary fiber samples were obtained after drying. The eutectic temperature of primary fiber was determined by resistance method. The freeze-drying curve of primary fiber was obtained. The pore structure of primary fiber was characterized by mercury intrusion method. The effects of blast drying, air-drying and freeze-drying on morphology of sample influences. The results showed that the eutectic temperature of primary fiber was -55 ℃. The shrinkage of samples and the adhesion between fibers were observed by blast drying. The original morphology was destroyed. The cross-sectional area and perimeter of samples were reduced by 20.66% 10.67%, the rate of change of shape coefficient is 3.52%. However, the cross-sectional area and perimeter of freeze-dried samples only contracted 1.21% and 1.15%, respectively, and the rate of change of shape coefficient was 1.13%. Freeze-drying effectively preserves the inherent native structure of PAN primary fibers and can be used to prepare samples for various analyzes.