研究了添加剂对PI取向性能、耐摩擦性、热稳定性以及透光率的影响。用均苯四甲酸二酐(PM-DA),对苯二胺(PDA),4-已氧基联苯酚-3’,5’-二胺基苯甲酸酯(C6-BBDA),制备了三元共聚型PI取向膜,并采用添加剂(封端剂和交联剂)对PI改性。通过调节添加剂的组成制备了4种PI。利用红外光谱仪(FT-IR)、热失重分析仪(TGA)、紫外分光光度计(UV-Vis)、偏光显微镜(POM)和预倾角测试仪对合成的PI进行了结构表征和性能测试。研究发现LC分子在4种PI膜上都获得了均匀的垂直取向;添加交联剂的PI膜具有良好的耐摩擦性,经摩擦强度为600mm摩擦后,仍对LC分子具有垂直取向的能力;加入添加剂的PI膜具有良好的热稳定性,此外,加入添加剂的PI膜仍具有较高的透光率。
The effect of the additive on alignment property,rubbing-resistance,thermal stabilities and transmittance of PI was investigated.The PI alignment film was prepared by pyromellitic dianhydride(PMDA),p-phenylenediamine(PDA) and 4-hexyloxy-bip henyl-3',5'2-diaminobenzoate(C6-BBDA).The PI was modified by the additive(end capping agent and crosslinking agent).The structures and properties of PI were measured with infrared spectrometer(FT-IR),thermogravimetric analysis(TGA),ultra-visible spectrometer,polarized microscopy and pretilt angle tester.It was found that uniform LC vertical alignment was induced by four kinds of PI films.PI film modified with crosslinking agent showed excellent rubbing-resistance and still kept LC vertical alignment after strong rubbing in rubbing strength as 600mm.PI films with the additives possessed good thermal stabilities.Moreover,PI films with the additives had high transmittance.