对位芳纶结构对其浆粕性能的影响

Effect of para-aramid fiber structure on pulp properties

采用黏度法、X射线衍射法、光学显微镜及扫描电镜、差示扫描量热等手段对对位芳纶短纤维的分子结构、相对分子质量（MW）、聚集态结构、表面形貌结构和热性能进行了研究;采用槽式打浆机对对位芳纶进行打浆制得对位芳纶浆粕,探讨对位芳纶的结构对其浆粕化工艺及浆粕性能的影响.结果表明：对于特性黏数为1.80 ～ 3.97 dL/g的对位芳纶,其MW为（1.29～2.72） ×104,结晶度为46.51％～57.10％,最大失重率为37.74％ ～ 46.90％;对位芳纶表面光滑,纤维呈刚性伸直状,MW大的芳纶,其纤维表面分丝帚化;MW和结晶度是影响对位芳纶强度、浆粕化工艺以及浆粕性能的重要因素,在制备对位芳纶浆粕时,应选择MW大于2×104,作用力大于纤维内部的次价力而小于主价力,在保证纤维长度的情况下,作用力越大,分丝帚化效果越好.

The molecule structure,relative molecular mass （MW）,aggregation structure,surface morphology and thermal properties of para-aramid staple fiber were studied by viscometry,X-ray diffraction method,optical micrography,scanning electron microscopy and differential scanning calorimetry.Para-aramid pulp was prepared by using trough-type beater.The effect of the structure of para-armide fiber on the pulp process and properties was discussed.The results showed that para-aramid fiber exhibited MW of （1.29-2.72） × 104,crystallinity of 46.51％-57.10％ and the maximum weight loss 37.74％-46.90％ as the intrinsic viscosity was 1.80-3.97 dL/g; para-aramid fiber was of smooth surface and rigid stretched appearance,and the fibrillation occurred on the surface of armaid fiber with high MW ; MW and crystaltinity was the essential factor bearing upon the strength of para-aramid fiber and pulp process and properties ; the para-aramid fiber for pulp making should possess MW over 2 ×104 and the force higher than the non-chemical bond force but lower than the chemical bond force; the greater the force,the better the fibrillation effect at a desired fiber length.