水洗方法对PAN原丝及其碳纤维结构与性能的影响

Effect of washing method on structure and properites of PAN precursor and PAN-based carbon fiber

在聚丙烯腈(PAN)基碳纤维生产中,分别采用浸涌式水洗、拍打式水洗、超声式水洗3种方法对PAN原丝进行水洗,讨论了PAN原丝的线密度对水洗效果的影响,以及3种水洗方法对PAN原丝及其碳纤维的结构与性能的影响。结果表明:在水洗流量1 m3/h、水洗温度60℃、水洗时间1.2 min的条件下,随着PAN原丝线密度的增加,原丝中二甲基亚砜(DMSO)残留量增加,浸涌式水洗受原丝线密度的影响较大,超声式水洗受原丝线密度的影响较小;在PAN原丝线密度为4.0 dtex时,PAN原丝经浸涌式、拍打式、超声式水洗后,DMSO残留量分别为1 000,200,90μg/g,相应碳纤维强度分别为5 139,5 120,4 930 MPa;浸涌式水洗对PAN纤维的损伤较小,超声式水洗对PAN纤维的损伤较大。

Polyacrylonitrile （PAN） fiber was washed through three kinds of washing methods, i.e. dipping and gushing meth- od, flapping method, ultrasonic method, during the production of PAN-based carbon fiber. The effects of the linear density of PAN precursor on the washing effect and the washing methods on the structure and properties of PAN precursor and PAN-based carbon fiber were discussed. The results showed that the dimethyl sulfoxide （DMSO） residue of the precursor was increased with the increase of the linear density of PAN precursor under the conditions as followed ： washing flow 1 m^3/h, washing temperature 60 ℃, washing time 1.2 min; the linear density of the precursor greatly affected the dipping and gushing method, but slightly affected the ultrasonic method; the DMSO residue of the PAN precursor was 1 000, 200, 90 μg/g,respeetively, after the dipping and gushing method, flapping method and ultrasonic method, corresponding to the carbon fibers with the strength of 5 139, 5 120,4 930 MPa, when the linear density of PAN precursor was 4.0 dtex; and the dipping and gushing method slightly impacted the PAN-based carbon fiber when the ultrasonic method greatly damaged the fiber.