干湿法含硼高强高模PVA纤维的制备及其结构性能研究

以二甲基亚砜/水(DMSO/H2O)为混合溶剂,硼酸为交联剂,采用干湿法纺丝制备含硼高强高模聚乙烯醇(PVA)纤维(简称PVA-B纤维),研究了其结构性能。结果表明:随着硼酸含量的增加,PVA-B纤维的断裂强度和初始模量先增大后减小,断裂伸长率先减小后增大,当硼酸质量分数(硼酸质量相对PVA质量)为0.6%时,PVA-B纤维的强度和模量达到最大,其值分别为15.45cN/dtex和412.76cN/dtex。与PVA纤维相比,硼酸质量分数为0.6%的PVA-B纤维的断裂强度和初始模量均大幅度提高,且其纤维的取向度、结晶度、熔点、最大热失重速率的温度均得到提高,其取向度为96.73%,结晶度为75.40%,熔点为239.5℃,最大热失重速率的温度为378.6℃。

Preparation and structural properties of boron-containing high-strength high-modulus PVA fiber by dry-wet spinning process

Boron-containing high-strength high-modulus polyvinyl alcohol(PVA)fibers(PVA-B fiber)were prepared by dry-wet spinning using dimethyl sulfoxide/water(DMSO/H 2O)as mixed solvent and boric acid as crosslinking agent.The structural properties of PVA-B fiber were studied.The results showed that the breaking strength and initial modulus of PVA-B fibers increased first and then decreased,and the elongation at break decreased first and then increased with the increase of boric acid content;the strength and modulus of PVA-B fibers were maximized as 15.45 cN/dtex and 412.76 cN/dtex,respectively,when the boric acid mass fraction(based on PVA)was 0.6%;compared with those of PVA fibers,the breaking strength and initial modulus of PVA-B fibers containing 0.6%boric acid by mass fraction were greatly improved,and the degree of orientation,crystallinity,melting point and the temperature of maximum thermogravimetric rate of PVA-B fibers were all increased;and the degree of orientation,crystallinity,melting point and temperature of maximum thermogravimetric rate of PVA-B fibers were 96.73%,75.40%,239.5℃and 378.6℃,respectively.