Poly(Styrenesulfonic Acid)-based Liquid Crystal Supermolecules

Liquid crystalline ionomer is a kind of supramolecular liquid crystal with anion and cation,which combines the special optical properties of liquid crystal polymers and the compatibilization of ionomers,and expands the application range of the original liquid crystal polymers.The combination of new polymers with various structures and compositions has important academic value.It is applied in many discipline such as chemistry,materials science,electronics,physics,etc.Moreover,it shows good application prospects in blending materials,optics,information,membrane materials and other fields.Sulfonic acid group is a strong polar group.When there are a few sulfonic acid groups in a liquid crystalline polymer,it can exhibit polarity.Liquid crystalline ionomers with such sulfonic acid groups are studied in supramolecular liquid crystals and composite materials,and the preparation and other aspects play a role in capacity expansion and enhancement.In this paper,a new series of side chain liquid crystal ionomers containing sulfonic acid groups were designed and synthesized.Firstly,three kinds of monomers were designed and synthesized,which are named as iso-nicotinic acid p-diphenol ester(M1),isosorbide isotonic acid ester(M2),and isonic acid cholesteryl ester(M3).M1,M2 and M3 are respectively salted with polystyrene sulfonic acid and phthalocyanine to synthesize S1,S2 and S3 series supramolecular liquid crystals.Monomers M1 and M3 are reacted with polystyrene sulfonic acid and phthalocyanine to synthesize S4 series.For the supramolecular liquid crystals,S6 and S5 series supramolecular liquid crystals were respectively synthesized by adding graphene oxide to S1 and S4 series polymers;and graphene oxide was added to S2 and S3 series polymers respectively to synthesize S7 and S8 series supramolecular liquid crystals.Three kinds of liquid crystal monomers and eight series of supramolecular liquid crystals have not been reported,so the research of this thesis is original.The molecular structure,thermal properties and liquid crystalline properties of the monomers and the synthesized liquid crystal polymers were characterized and analyzed by FT-IR,1H-NMR,DSC and XRD.The results show that the chemical structures of the monomers and liquid crystal polymers are consistent with the molecular structure design.M1 and M3 are thermotropic liquid crystals.M1 exhibits a nematic phase texture and spherule texture,and M3 shows a cholesteric focal conic texture.All the eight series of polymers appear colorful liquid crystal textures.Tg and Ti of the supramolecular liquid crystal polymers increased with the increase of the phthalocyanine.The addition of the appropriate amount of graphene oxide increased the Tg and Ti of the polymers.The conductivity of the polymers increase with the increase of the content of phthalocyanine,and the addition of an appropriate amount of graphene oxide increases the conductivity of the polymers.Research in this paper not only has important theoretical significance,but also provides scientific data and certain technical support on the further application of supramolecular liquid crystal polymers.