Synthesis and characterization of side chain liquid crystal M5MPP/MMEANB copolymers containing NLO active group

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, H-1 NMR, POM a nd WAXD were used to study the structure, phase behavior and mesophase text ure of this series of SCLC copolymers. The researches show that polymer PM5 MPP and copolymer M5MPP/MMEANB are enantiotropic liquid crystalline polymer s, but polymer PMMEANB has no liquid crystalline properties. DSC results sh owed that the thermal stability of the mesophase of this series of copolyme rs was enhanced by the existence of intermolecular electron donor-acceptor interaction. It was found that the temperature range of the mesophase of th e copolymers was broadened with increasing 4-nitroazobenzene units. The foc al-conic texture observed by POM indicated that this series of the copolyme rs possessed the characteristics of smectic liquid crystal.