1、 CAS # 89-32-7

2、physicochemical properties: white to light yellow crystalline powder, melting point 286 ° C, density 1.68 (20 ° C), boiling point 397.4 ° C, easily absorbsolated in air to benzene 4

3、 Uses: Used to prepare polyimide resins, polyimide films, polyimide fibers, powder coating extractor, advanced electrical insulating materials, and the like.

1,、CAS # 89-05-4

2、physicochemical properties: white crystalline powder, melting point 281 ° C, density 1.79 (20 ° C). At temperatures above the melting point, the dehydration becomes a phenylene dihydride.

3、Uses: Used to prevent powder coating extractor, xenobenzene tetractate plasticizer, can also prepare polyimide resins.

Along with the development of production technology of Pyromelitic Dianhydride (PMDA),PMDA technical process have a higher performance request for PMDA catalyst.Hope Chemical has started research on PMDA production and PMDA process since 1995. In 2003,We developed independently efficient PMDA catalyst. In currently，we have developed different types of catalysts for industry application，just like GHB-1,GHC-1,GHAB-2 double layer. With the properties of high selectivity, high yield and long life , these types of catalyst provide quality guarantee for improving crude PMDA refining efficiency and lower down production cost of PMDA.