干法纺丝低温水溶聚乙烯醇纤维的制备

Preparation of low-temperature water-soluble polyvinyl alcohol fiber by dry spinning process

以聚合度为1 700±50、不同醇解度的聚乙烯醇(PVA)为原料,按PVA-1795∶PVA-1788质量比6∶4进行共混,采用干法纺丝制备低温水溶PVA纤维,并对水溶纤维的结晶度、取向度、晶面间距、晶粒尺寸、溶断温度和溶断收缩率进行表征。结果表明:纤维的溶断温度主要取决于纤维拉伸倍数和拉伸温度,拉伸倍数越高、拉伸温度越低,溶断温度也越低;纤维的溶断收缩率不仅与取向度有关,也与晶粒尺寸有关,取向度相差不大的情况下,晶粒尺寸越大,所得纤维的溶断收缩率越高;在180℃下进行4倍拉伸时,可得到拉伸强度为5.45 cN/dtex,溶断温度为18℃,溶断收缩率为27%的低温水溶PVA纤维。

Low-temperature water-soluble polyvinyl alcohol （PVA） fibers were prepared by blending PVA with the polymeriza- tion degree of 1 700 ± 50 and different alcoholysis degree, i.e. PVA-1795 and PVA-1788 ,at the mass ratio of 6 ： 4 via dry spin- ning process. The crystallinity, orientation degree, crystal plane spacing, crystal size and dissolving temperature and dissolution shrinkage of the water-soluble PVA fiber were characterized. The results showed that the dissolving temperature of the fibers dom- inantly depended on the draw ratio and stretching temperature; the fiber had the lower dissolving temperature at the higher draw ratio and the lower stretching temperature; the dissolution shrinkage of the fiber was not only related to the orientation degree but also to the crystal size, which was increased with the increase of crystal size at the similar orientation degree ; and the low-temper- ature water-soluble PVA fiber can be produced with the tensile strength of 5.45 cN/dtex, dissolving temperature 18 ℃ and dis- soution shrinkage 27% at the stretching temperature of 180 ℃ and draw ratio of 4.