I_2/KI溶液改性PVA纤维的制备及其性能研究

Preparation and properties of PVA fiber modified with I_2/ KI solution

采用摩尔浓度比为1∶2的I2/KI溶液对聚乙烯醇(PVA)初生凝胶丝条进行超声浸泡处理,制备了改性PVA(I-PVA)纤维;探讨了I2/KI溶液浓度对纤维拉伸性能的影响,并对I-PVA纤维的结构与性能进行了研究。结果表明:I2在PVA纤维中主要以I-5的形态存在,I2的加入会阻碍PVA分子链之间的氢键形成,纤维的拉伸倍数得到提高,强度和模量也有提高;I-PVA纤维的最佳热拉伸温度为150℃,比未改性PVA纤维最佳热拉伸温度降低了50℃;PVA初生纤维在空气中拉伸3倍,采用0.1 mol/L的I2/KI溶液于40℃超声浸泡1 h后,于150℃拉伸10倍,得到的I-PVA纤维的断裂强度可达14.7 c N/dtex,比未改性PVA纤维提高9.7%,最大拉伸倍数提高到36。

A polyvinyl alcohol（ PVA） as-spun fiber was prepared by gel spinning process and was produced into a modified PVA（ I-PVA） fiber by ultrasonic immersion treatment in I2/ KI solution at the molar concentration ratio of 1∶2. The effect of I2/KI solution concentration on the tensile properties of the fiber was discussed. The structure and properties of I-PVA fiber were studied. The results showed that I2 existed in PVA fiber in the form of I-5,and the addition of I2 could hinder the hydrogen bond formation between PVA molecular chains and thus increase the draw ratio,strength and modulus of the fiber; the optimal heat drawing temperature for I-PVA fiber was 150 ℃,with a decrease of 50 ℃ as compared with that for unmodified PVA fiber; and the obtained I-PVA fiber had the breaking strength up to 14. 7 c N / dtex,with a growth of 9. 7% as compared with unmodified PVA fiber,and the maximum draw ratio up to 36 when the as-spun PVA fiber was drawn at 3 time in air prior to 1-hour ultrasonic immersion in 0. 1 mol / L I2/ KI solution at 40 ℃ and then was drawn at 10 time at 150 ℃.