Synthesis And Characterization Of Two Series Of Main-chain Liquid Crystalline Ionomers Containing Sulfonic Ion

Liquid crystalline ionomers (LCIs) are liquid crystalline polymers containing ionic groups and the properties of LCIs are superior to the LCPs because of the compatibilization in composites by the function of ionic groups between the molecule chains. Therefore, LCIs are one new kind of function polymer materials and have been one of important research project in the field of LCPs. However, to the best of our knowledge, research on LCIs is few reported at present, so it is necessary and interesting to study LCIs, which provides theoretical basis and novel thought to synthesize and prepare the composites with other polymers, especially in the fields of the blends with advantageous properties. Besides, LCIs can be useed as the additive of ultrafiltration membrane, improve the water flux and filterableness of membrane, this paper is after search a large number of documents and design the experimental program.In this paper, we synthesize 4,4'-dicarboxydihenyi ether chloride and sebacic chloride, which structures are characterized by IR. The MLCI-S1-n and MLCI-S2-n are prepared by a solution condensation polymerization reaction from different proportion of 4,4'-dicarboxydihenyi ether chloride, sebacic chloride,4, 4'-biphenyldiol, and brittle yellow(BY).,The MLCI-S1-n is synthesized by the constant amount of 4,4'-biphenyldiol and brittle yellow (mole amount 1%), but increasing the amount of 4,4'-dicarboxydihenyi ether chloride in the MLCI-S1-n. The liquid crystalline properties are characterized by FT-IR, DSC, TGA and POM. The main-chain liquid crystalline ionomers MLCI-S1-0～MLCI-S1-4 are all nematic, however MLCI-S1-5 and MLCI-S1-6 have no liquid crystalline property due to enhancing the rigidity of MLCI-S1-5 and MLCI-S1-6. Tg and Tm of MLCI-S1-0-MLCI-S1-6 increase with the increasing of 4,4'-biphenyldiol. TGA analysis results show that all polymers exhibit good thermal stability.The MLCI-S2-n is synthesized by 4,4'-dicarboxydihenyi ether chloride and sebacic chloride (mole ratio 1:9) for thermal and liquid crystalline properties of MLCI-S1-n. Their structures are characterized by FT-IR and UV, and the liquid crystalline properties are characterized by DSC and POM. The results show that the addition of ions don't change the liquid crystal tape of MLCI-S2-n, they are all nematic liquid crystal. The liquid crystalline properties of MLCI-S2-n are weakened with the increasing of BY. Tg and Tm of MLCI-S2-n are increased, however, the Ti becomes increase first and then decrease with the increasing of BY. The liquid crystalline mesogenic regions of the MLCI-S2-n become broad first and then narrow with increasing sulfonic ion content. The decomposed temperature of MLCI-S2-n decrease with the increasing of BY. So the MLCI2-n exhibited bad thermal stability due to addition of ion.