Synthesis And Properties Study Of Crosslinked Polymers Containing Imidazole Ionic Bromine Salt

Cross-linked ionic polymer is to connect the polymer with ionic groups on the molecule chains. It is different with homogeneous polymer that ionomer generate ionic rich aggregates in a non-polar polymer matrix due to the interaction of inner ionic groups. This interaction of ions have a strong effect on the properties and applications of polymers, thus widely to research and development. Through molecular design, ionic liquid crystal polymer synthesized by the ionic polymeric monomer containing a liquid crystal group can further improve the properties of ionic polymer, and expand ionomer application.In this paper, firstly different carbon chain lengths of 1-vinylimidazole double salt were synthesized; Secondly N-methylimidazole or 1-vinylimidazole bromide modified for nitroazobenzene liquid crystal compound were synthesized. Finally, the imidazole ionomer was synthesized by copolymerization of photochromic monomer 4-allyoxy-4’nitroazobenzene and cross-linker imidazole ionic salt on polymethylhydrosiloxane, and the imidazole ionic liquid crystal polymer was prepared by the copolymerization of 1-vinylimidazole bromide modified nitroazobenzene liquid crystal compound and cross-linker(EGDMA). Both the intermediates and targeted product have been characterized by FT-IR and 1H NMR to investigate their structures, and the studies of their optical properties and thermal properties have been carried out by UV-vis absorpotion spectra, polarizing microscope and thermogravimetric analysis.In UV-vis absorption spectrum, imidazole bromide modified nitroazobenzene liquid crystal compound exhibited an absorption maxima at about 378 nm, which were related to π-π* trasition band of the trans-azobenzene. Imidazole salts have no effect on the molecular arrangement and structure in solution. By the polarizing microscope, imidazole bromide modified nitroazobenzene liquid crystal compound showed smectic A phase with focal conic texture. The liquid crystal state can be stable over wider temperature range due to the presence of imidazole ionic salts. Finally, some of the optical properties and crystal properties of ionic polymer still need further research.