Study On The Preparation And Performance Of Polybenzimidazole Resin

In this dissertation,polybenzimidazole resins,(PBI) history of development,the current state of development,synthetic methodology,type,performance,application and the synthesis of monomer is first briefed introduced. The paper has studied take 3,3'-diaminobenzidine and 3,3',4,4'-Tetraaminodiphenylmethane as four amine monomers , react with many kinds of binary acid to yield two series of polybenzimidazole resins. The structure and properties of copolymers were investigated by ¹HNMR,¹³CNMR,FT-IR,DSC,TGA etc,and we inspected polymers, solubility and thermal properties. The concrete research content and the result are as follows:1) 3,3'-diaminobenzidine was prepared with 4,4'-diamin- obiphenyl as starting material in five steps by N-acylation,nitration,hydrolysis,reduction and neutralization. Synthetic route of the compounds were optimized by use the stannous chloride and hydrochloric acid during the restore process. In comparison to the reduction of hydrogen under high pressure condition which described in the literatures,this synthetic strategy is superior in reaction conditions,simple disposal,and easily obtained high yield and purity. 2)O-nitroaniline, formaldehyde as raw materials to synthesize 3,3'-dinitro-4,4'-diaminodiphenylmethane, through the reduction into 3,3',4,4'-Tetraaminodiphenylmethane. 3)In the polymerization process,we choose the common solution polymerization method, polyphosphoric acid as solvent,nitrogen protection,under high temperature,using 3,3'-diaminobenzidine and 3,3',4,4'-Tetraaminodiphenylmethane react with p-phthalic acid,m-phthalic acid,biphenyl-4,4'-dicarboxylic acid,2-fluoroterephthalic acid,4-nitrobenzene-1,3-dioic acid,2-nitroterephthalic acid. Generated two types of polybenzimidazole resins, and tested their performances.