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Indexed by:期刊论文

Date of Publication:2001-01-01

Journal:Acta Polymerica Sinica

Included Journals:Scopus、PKU

Issue:2

Page Number:279-280

ISSN No.:10003304

Abstract:A novel unsymmetrical dianhydride containing 4-(4-hydroxylphenyl)-2,3-phthalazin-1-one was synthesized in order to improve the solubility of aromatic polyimides according to the principle of designing new monomers. This article reported a series of polyimide random copolymers derived from 4,4  -diamino diphenyl sulfone (DAPS) ,4,4  -oxyl dianiline (ODA) and the new dianhydride-2-(3,4-dicarboxyl-phenyl)4-(3  ,4  -dicarboxyl-phenyl- oxyl)-phenyl-2,3-phthalazine-l-one dianhydride (DAH4) by "one-step" solution polycondensation in m-cresol with catalystic amount of isoquinoline at 200  C. Some properties of the copolymers were investigated by DSC, TG and mechanical analysis. The result shows that the    inh of copolymers is between 0.64 to 0.71 dL/g in m-cresol at 25  C, and the T g of the copolymers are higher than that of pure poliymides containing 4,4  -oxyl dianiline (polymer 5). The relationship between T g and mole percent of DAPS is not obvious. Degradation temperature for 5% weight loss (T d5) of the copolymers occurs all above 470  C in air. The mechanical properties of the copolymers are lower owing to introducing sulfone groups into polymer's backbone. In sharp contrast,the copolymers have good solubility and can be easily soluble in 1,1,2,2- tetrachloroethane (TCE), N, N- dimethylacetamide (DMAc), N- methyl-2-pyrrolidinone (NMP), m-cresol and pyridine. Furthermore, the copolymers have better solubility in dimethyl sulfoxide (DMSO) and chloroform than the polyimide derived from DAH4 and ODA.