空气层高度对干湿法纺聚乙烯醇初生纤维结构的影响

Effect of air gap height on structure of as-spun polyvinyl alcohol fiber prepared by dry-wet spinning

采用聚乙烯醇(PVA)进行干湿法纺丝,于不同空气层高度下制备PVA初生纤维,研究了空气层高度对PVA初生纤维线密度、取向因子、结晶度、熔点及初生纤维分子链缠结结构的影响。结果表明:由于受重力和挤出胀大作用的双重影响,随空气层高度的增加,PVA初生纤维线密度呈先增加后减小的趋势,而其声速取向因子则呈先减小后增加的趋势;PVA初生纤维的结晶度、晶区取向因子以及熔点都随空气层的高度增加而呈增加的趋势;空气层阶段PVA分子链的缠结程度随着空气层高度的增加逐渐降低。

An as-spun polyvinyl alcohol （PVA） fiber was prepared from PVA by dry-wet spinning at different air gap height. The effects of air gap height on the linear density, orientation factor, crystallinity, melting point and molecular chain entanglement structure of as-spun PVA fiber were studied. The results showed that the linear density of the as-spun PVA fiber was increased and then decreased with the increase of air gap height due to the dual influence of gravity and extrusion swell when the sonic orientation factor tended to change firstly downward and then upward; the crystallinity, orientation factor in crystalline region and melting point of as-spun PVA fiber were increased with the increase of air gap height; and the entanglement degree of PVA molecular chain was gradually decreased with the increase of air gap height.