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研究了水洗条件对聚丙烯腈(PAN)水洗丝条结构和力学性能的影响。用万能材料测试机、XRD、SEM、压汞仪测试纤维的力学性能、晶态结构、表面形态和孔结构,得到结构对力学性能的影响规律。结果表明:随着水洗温度升高,丝束的最大应力和最大载荷降低;水洗温度从55℃增大到90℃,结晶度从64.84%降低到57.73%,晶粒大小从4.034nm变为5.007nm;水洗温度升高,丝表面出现更加明显的纵向沟槽,表面缺陷增多,丝的直径也变得不均匀,孔隙率和孔径变小,微孔逐渐增多;随着结晶度降低、晶粒尺寸变大、表面缺陷增多,丝的力学性能随之下降;相同温度,超声波使纤维的孔径和孔隙率变小,同时使表面缺陷增多,所以超声波对丝的力学性能影响不大。
The effect of washing conditions on the structure and mechanical properties of polyacrylonitrile (PAN) was studied. The mechanical properties, crystal structure, surface morphology and pore structure of the fiber were tested by universal testing machine, XRD, SEM and mercury porosimetry. The influence of structure on the mechanical properties was obtained. The results showed that the maximum stress and the maximum load of the tow decreased with the increase of water washing temperature. The temperature of water washing increased from 55 ℃ to 90 ℃, the crystallinity decreased from 64.84% to 57.73%, and the grain size changed from 4.034nm to 5.007 nm. When the washing temperature increases, the longitudinal groove appears more obvious on the surface of the wire. The surface defects increase, the diameter of the wire also becomes uneven, the porosity and pore size become smaller, and the micro-pores gradually increase. As the crystallinity decreases, The size and the surface defects increase, the mechanical properties of the wire decrease; the same temperature and ultrasonic wave make the fiber pore size and porosity become smaller, and make the surface defects increase, so the ultrasonic wave has little effect on the mechanical properties of the wire.