【摘要】 为了改善聚酰亚胺对介质的粘附性和提高对液晶分子的定向功能,报道了用甲苯二异氰酸酯(TDI)作为扩链剂对含—NH2—端基的聚酰胺酸预聚体进行扩链改性,合成了新型结构的聚脲酰亚胺聚合物。通过红外分析和TGA对此聚合物的热稳定性进行了研究,以DSC和TMA对此聚合物的相分离进行了讨论。以DEA方法,在0.1~105Hz宽频范围和0~350°C区间完整地测定了聚脲酰亚胺的介电常数ε′~温度的频率谱和介电损耗tanδ~温度的频率谱,符合液晶分子定向膜材料的电性能要求。从测定的此聚合物对液晶分子定向性能参数可知,聚脲酰亚胺是一类可供TN—LCD、HTN—LCD等显示器生产的良好的定向膜材料。更多还原

【Abstract】 A novel type of polyureas-imide was prepared by a reaction of amino-terminated prepoly(amic acid) and TDI,which was used as a chain extender to improve the adhesion to medium and the alignment ability for liquid crystal of polyureas-imide.The thermal stability was studied via IR and TGA.The results of DSC and TMA showed that polyureas-imide exhibited a well phase-separated morphology.By dielectric analysis method,the charts of ε′～T and tanδ～T were respectively determined on brand-frequency from 0.1 Hz to 10~5 Hz and temperature from 0℃ to 350℃,which showed that the polyureas-imide met the demand of alignment film material.From the values of the alignment ability of this material for liquid crystal,it could be concluded that polyureas-imide was a sort of good alignment film material for TN-LCD or HTN-LCD etc.更多还原