纺丝溶液浓度对UHMWPE冻胶纤维萃取及拉伸性能的影响

摘要

通过冻胶纺丝法制备了纺丝溶液质量分数为8％～16％的超高相对分子质量聚乙烯(UHMWPE)冻胶纤维.研究了不同浓度冻胶纤维的相分离、萃取动力学、结晶性能、热性能和拉伸性能.结果表明:冻胶纤维成形之后的相分离过程开始60 min内较为剧烈,在约2000 min达到相分离平衡；冻胶纤维的萃取除油率随浴比的增大或萃取时间的延长而增大,最佳萃取浴比和萃取时间为10 mL/g和2min;纤维的熔融温度和结晶度均随UHMWPE浓度的增加而增加,萃取干燥纤维的熔点和结晶度均高于其冻胶纤维；萃取干燥及拉伸后纤维的力学性能均随纺丝溶液浓度的增加而降低；随冻胶纤维内溶剂的去除及三级拉伸的进行,纤维结晶度增大而晶粒尺寸变小.%Ultrahigh-relative molecular mass polyethylene (UHMWPE) gel fibers were prepared from 8% - 16% spinning solution by mass fraction by gel spinning process. The phase separation,extraction kinetics, crystalline, thermal and tensile properties were studied for gel fibers of different concentrations. The results showed that the phase separation process proceeded actively in 60 min after the formation of gel fibers and achieved the equilibrium state in 2 000 min. The extraction oil removal rate of gel fibers increased while raising the extraction bath ratio or prolonging the extraction time. The optimal extraction bath ratio and extraction time were 10 mL/g and 2 min, respectively. The melting point and crystallinity of the fibers were increased with the increase of UHMWPE concentration. The extracted dried fibers had the melting point and crystallinity higher than those of gel fibers. The mechanical properties of extracted dried fibers and drawn fibers were both decreased with the increase of the spinning solution concentration. The crystallinity of gel fibers was increased and the crystal size was decreased during the process of solvent removal and the three-stage drawing.