干喷湿纺中凝固牵伸对碳纤维前驱体PAN初生纤维的影响

Study on the Effect of Coagulation Drawing on Polyacrylonitrile Nascent Fibers During Dry-jet Wet Spinning

为了研究PAN纤维干喷湿纺中凝固浴牵伸的作用机理,采用DMSO水溶液作为凝固浴,利用纤维强伸度仪、分析天平、X射线衍射仪、电子探针等手段,研究了干喷湿纺中凝固牵伸对PAN初生纤维及最终原丝结构及性能的影响。结果表明,干喷湿纺中,在凝固浴浓度(65%)、温度(20℃)、空气层厚度(2 mm)等条件下,随凝固浴牵伸的增加,初生纤维及PAN原丝的孔隙率逐步降低,结晶度逐渐增大,初生纤维表现出较高的断裂强度,纵表面更加光洁,横截面更加致密;适当调整凝固浴牵伸,得到了纤度1.01 dtex,强度7.52 cN/dtex的聚丙烯腈原丝。

To study the effect of coagulation drawing during dry-jet wet spinning on the structure and properties of polyacrylonitrile nascent fibers and precursors, fiber intensity and elongation testing machine, analytical balance, XRDS, EMPA and so on were used. Results indicated the rules of coagulatinn drawing on the nascent fibers. When DMSO/H20 system was used as coagulation bath during dry-wet spinning, coagulation bath concentration was 65 %, coagulation temperature was 20 ~C, air gap distance was 2 mm, hole ratios of polyacrylonitrile nascent fibers and precursors reduced with the rise of coagulation drawing, crystallinity gradually increased, the nascent fibers with upper breaking intensity, glabrous surface and compact microstructure were achieved. If the coagulation drawing was appropriate, the excellent polyacrylonitrile precursor was obtained, whose fiber fineness was 1.01 dtex and intensity was 7.52 cN/dtex.