Two polyimide(PI) films were prepared by reacting the diamine 4,4'-oxydianiline(ODA) with two dianhydrides,pyromellitic anhydride(PMDA) and hydrogenated pyromellitic anhydride(HPMDA),respectively,via a two-step polymerization procedure.

Recycle of pyromellitic dianhydride from waste of production;

Pretreatment of high concentration pyromellitic dianhydride production wastewater by Fenton reagent

The uses and manufacture processes of pyromellitic dianhydride in coatings industry,such as durene process,alkylation process of 1,2,4-trimethylbenzene and carbon monoxide process were briefly introduced.

Trimellitic anhydride and o-phthalic anhydride are the mainly by-products in the producing process of pyromellitic anhydride.

Advances in catalysts for obtaining pyromellitic dianhyride by catalytic gaseous phase oxidation;

A catalyst for obtaining pyromellitic dianhyride by catalytic gaseous phase oxidation from durene are developmented.

The preparation methods of pyromellitic acid dianhydride from durene were also briefly introduced.

Pyromellitic acid dianhydride,also named 1,2,4,5-benzene tetracarboxylic acid dianhydride(abbreviated to PMDA),is the important material of organic synthesize industry and the essential raw material of developing the new chemical material and high odditional fine chemistry Nowadays the method of producuction of PMDA by air phase oxidation is widely used in many factories at home and abroad.

Durene is an important organic chemical raw material, and it is mainly used to produce pyromellitic acid dianhydride, therefore, the durene is considered as the most economical and ideal raw material to produce polyimide film.