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This article first polyimide recent history and current status of the development , synthesis and modification methods , properties and application are briefly introduced , and secondly, reported a class of main chain structure containing tons of new polyimides. Papers include: 1.9,9 two ( 4 -hydroxyphenyl ) xanthene (BHPx) based monomer preparation . In xanthene ketone as starting material, 9,9 role of thionyl chloride . Dichloro- xanthene intermediate, followed by substitution reaction with phenol system. Experimental Methods The Task Force continues to improve , the yield was 85%. 2.9,9 - bis (4 - amino- phenoxy -phenyl ) Preparation of xanthene . First, a 9,9 bis ( 4 -hydroxyphenyl ) xanthene obtained chloronitrobenzene and 9,9 - bis (4 - nitro -phenyl ) xanthene , and then was dried over anhydrous ethanol dinitration the hydrazine hydrate in / palladium carbon reduction obtained 9,9 - bis (4 - amino- phenoxy -phenyl ) xanthene . 3 . A 9,9 - bis (4 - amino- phenoxy -phenyl ) xanthene , 4,4 ' - diaminodiphenyl ether (0DA) according to different proportion and pyromellitic dianhydride (PMDA) using two copolymerization step , synthesis of new structures containing polyimide t . The resulting polymer has good thermal stability and mechanical properties. It also explores the thermal cyclization cyclization method and chemical properties of polyimide . 4.9,9 bis [4 ( 4 amino- 2 trifluoromethylphenoxy ) phenyl ] xanthene (BTRFAPx) Preparation of From the base monomer 9,9 bis (4 - hydroxyphenyl ) xanthene (BHPx) and Bu chlorine two trifluoromethyl 5 nitrobenzene first obtained 9,9 bis [4 ( 4 Nitro 2 trifluoromethylbenzene oxy ) phenyl ] xanthene . The two nitro compounds by hydrazine hydrate in ethanol / palladium carbon reduction obtained 9,9 bis [4 ( 4 amino- 2 (trifluoromethyl) phenoxy ) phenyl ] xanthene (BTRAPx). 5 . A 9,9 bis [4 ( 4 amino- 2 trifluoromethylphenoxy ) phenyl ] xanthene , 4,4 ' - diaminodiphenyl ether (0DA) according to different proportion and biphenyl tetracarboxylic dianhydride fBPDA) m-cresol as solvent using one-step synthesis of novel trifluoromethyl -containing side groups and xanthene structure of polyimide . By terpolymer , the polyimide molecular chain side groups while introducing a trifluoromethyl group , a huge xanthene structure and an ether bond , to improve the solubility of the polymer . The fluorine-containing polyimide obtained in DMF, m-cresol, pyridine , tetrahydrofuran and the like solvents have good solubility in Central .
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