Synthesis And Characterization Of Soluble Polyimide Containing Tertiary Butyl,Ether Bond And Triphenylmethane Units

With its excellent comprehensive performance,aromatic polyimide is widely used in cutting-edge fields.However,some polyimides have poor solubility,which limits their application.Therefore,it is an important task to develop a polyimide with good solubility.In this paper,through molecular theoretical design,tertiary butyl,triphenylmethane,and ether bond units were successfully introduced into the diamine monomer,and then this type of diamine was polycondensed with four aromatic dianhydrides to obtain a number of new types of aromatics polyimide,and their performance were also tested.The research content is as follows:The first step:the preparation of bisphenol 1-?4-tert-butylphenyl?-1,1-bis?4-hydroxy?phenylethane?TBBHP?.Under the action of thioglycolic acid,HCl solution was used as catalyst,ice CH3COOH was used as solvent,phenol and4-tert-butylacetophenone were used as raw materials for reaction,and the target product TBBHP was successfully synthesized.The reaction time and material ratio of the reaction were also optimized.The second step:the preparation of dinitro compound 1-?4-tert-butylphenyl?-1,1-di[4-?4-nitrophenoxy?]phenylethane?TBBNP?.Anhydrous K2CO3 was used as the catalyst,the bisphenol TBBHP and p-chloronitrobenzene were the raw materials for the reaction,DMF was the solvent of the reaction.The target product TBBNP was successfully synthesized,and the reaction time and the ratio of the reaction were also optimized..The third step:the preparation of diamine 1-?4-tert-butylphenyl?-1,1-di[4-?4-aminophenoxy?]phenylethane?TBBAP?.The target product TBBAP was successfully synthesized by reduction of the dinitro TBBNP using iron powder reduction method,and its reaction time was optimized.The last step:Synthesis and characterization of new polyimide.Four kinds of aromatic dianhydride were polymerized with the synthesized diamine TBBAP,and four kinds of polyimide films and resins were synthesized by a two-step method.The results show that 6FDA,ODPA and BPDA-based PI resins are well soluble in common organic solvents such as NMP,concentrated H₂SO₄,DMAc,pyridine,THF,and CHCl₃;four kinds of films'glass transition temperature T_g?DSC?is between246?275?,5%weight loss temperature is above 501?;mechanical properties range from 67.2 to 88.6MPa.In addtion BTDA-based PI film,the other three types of PI have good transparency.