新型侧链液晶M5MPP/MMEANB高聚物的合成与表征

Synthesis and Characterization of Side Chain Liquid Crystal M5MPP/MMEANB Copolymers Containing NLO Active Group

以 4,4’ 二羟基联苯、4 硝基苯胺、二溴己烷、甲基丙烯酸、氯代乙醇为原料合成了单体甲基丙烯酸[5 (4’ 甲氧基联苯 4 氧基 )戊基 ]酯 (M 5MPP)、4 硝基偶氮苯基甲基 2 甲基丙烯酸酯基乙胺 (MMEANB) ,并完成了单体的聚合和共聚 ,得到了含有非线性光学活性基团 (NLO)的侧链液晶高分子 ,对其结构进行了表征 .结果表明 ,均聚物PM 5MPP及共聚物 (M 5MPP/MMEANB)属双向液晶高分子 ;PMMEANB属于非晶性高分子 .证实了分子间吸电子与给电子基团相互作用有利于提高液晶高分子热稳定性 ,共聚物 (M 5MPP/MMEANB)具有较宽的液晶相温度范围 .

A new series of side chain liquid crystal polymers based on the backbone of polymethacrylate containing 4-nitroazobenzene and 4-methoxybiphenyl group as side chain mesogen were prepared and characterized, FTIR, ~1H NMR, POM and WAXD were used to study the structure, phase behavior and mesophase texture of this series of SCLC copolymers. The researches show that polymer PM5MPP and copolymer M5MPP/MMEANB are enantiotropic liquid crystalline polymers, but polymer PMMEANB has no liquid crystalline properties. DSC results showed that the thermal stability of the mesophase of this series of copolymers was enhanced by the existence of intermolecular electron donor-acceptor interaction. It was found that the temperature range of the mesophase of the copolymers was broadened with increasing 4-nitroazobenzene units. The focal-conic texture observed by POM indicated that this series of the copolymers possessed the characteristics of smectic liquid crystal.