PREPARATION AND CHARACTERIZATION OF ORGANIC-SOLUBLE OPTICALLY TRANSPARENT POLYIMIDES FROM ALICYCLIC DIANHYDRIDE, BICYCLO[2.2.2]-OCT-7-ENE-2,3,5,6-TETRACARBOXYLIC DIANHYDRIDE

Organic-soluble optically transparent polyimides were prepared from al icyclic dianhydride monomer, bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracar boxylic dianhydride (BCDA). BCDA gives soluble polyimides with diamine s containing at least one flexible linkage such as ether, methylene an d sulfide. The polyimides have glass transition temperatures above 350 degrees C and a thermal decomposition temperature of 450 degrees C in an inert atmosphere. The polyimides form a tough film with an ultra-v iolet cut-off between 300 and 400 nm, which is comparable to that of a fluorinated polyimide.