聚合度与交联对碘系PVA偏光膜湿热稳定性的影响  

Effect of polymerization degree and crosslinking on hygrothermal stability of iodine-PVA polarizing films

作　　者：牛宇洁 赵明世 王兆飞 王晨曦 陆红波[2] 刘春华 张国兵[2] 丁运生 NIU Yu-jie;ZHAO Ming-shi;WANG Zhao-fei;WANG Chen-xi;LU Hong-bo;LIU Chun-hua;ZHANG Guo-bing;DING Yun-sheng(Anhui Key Laboratory of Advanced Functional Materials and Dervices,School of Chemical and Engineering,Hefei University of Technology,Hefei 230009,China;National Engineering Laboratory of Special Display Technology,Academy of Opto-Electronic Technology,Hefei Universily of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学化学与化工学院,先进功能材料与器件安徽省重点实验室,安徽合肥230009 [2]合肥工业大学光电技术研究院,特种显示技术国家工程实验室,安徽合肥230009

出　　处：《液晶与显示》2022年第10期1285-1292,共8页Chinese Journal of Liquid Crystals and Displays

基　　金：安徽省高校协同创新项目(No.GXXT-2019-001)

摘　　要：利用流延法制备聚乙烯醇(Polyvinyl Alcohol,PVA)偏光膜,通过正交实验确定碘化和交联时间,得到了不同聚合度以及交联与未交联的碘系PVA偏光膜。通过UV-Vis对湿热老化前后PVA偏光膜进行透过率测试和偏振度计算;利用Raman和XRD表征了不同聚合度偏光膜的化学形态和晶体结构;通过FT-IR分析湿热老化前后偏光膜的分子结构,系统探究了聚合度与交联对偏光膜光学性能及其耐老化的影响。研究结果表明,随着聚合度的增加,PVA膜对碘离子的吸附能力变强,偏光膜中I5-比重增加,其耐湿热老化性变好。从偏光膜的偏振度变化来看,聚合度越大其光学性能越好,老化失效率越低。在相同聚合度下,交联大幅提高了偏光膜的抗水解和耐湿热老化性能。高湿环境促进了偏光膜的解取向和交联结构中硼酯键的水解,导致膜结构和碘离子定向排列结构的破坏。碘离子流失是偏光膜失效的主要原因。The polyvinyl alcohol(PVA)polarizing films were prepared by the flow-casting method.The crosslinking or uncrosslinking iodine-PVA polarizing films with different polymerization degree were obtained after the determination of iodization and crosslinking time by orthogonal experiments.The transmittance was measured and the polarization degree of PVA polarizing film was calculated by using UV-Vis before and after hygrothermal aging tests.The chemical morphology and crystal structure of the polarizing films with different polymerization degree were characterized by using Raman and XRD.The molecular structure of the polarizing films with different polymerization degree before and after hygrothermal aging was analyzed by using FT-IR,and the effects of polymerization degree and crosslinking on the optical properties and aging resistance of the polarizing films were systematically investigated.The results show that as the polymerization degree increases,the adsorption of PVA films to iodide ions improves,the proportion of I5-in films increases,and the hygrothermal resistance aging performance of polarizing films becomes better as well.From the perspective of the change of polarization degree of polarizing films,the higher degree of polymerization is,the better optical performance and the lower failure rate of aging are.Under the same polymerization degree,the hydrolysis resistance and the hygrothermal resistance aging performance of the polarizing films are significantly improved after crosslinking.High humidity promotes the disorientation of polarizing films and the hydrolysis of borate ester bond in crosslinking structure,resulting in the destruction of films structure and iodide ions orientation.The iodide ions loss is the main reason for the failure of polarizing films.

关 键 词：偏光膜 聚合度 交联 湿热稳定性 

分 类 号：TQ317.6[化学工程—高聚物工业] TN27[电子电信—物理电子学]