This work is supported by the 863 Program (No. 2001AA335050) and the 973 Program (No. 2003CB615600) of MOST ofthe People's Republic of China.
Aromatic polybenzoxazole (PBO) precursor, hydroxy-substituted polyenaminonitrile, was prepared by direct polycondensation of 1,4-bis(1-chloro-2,2-dicyanovinyl)benzene (CCB) and 4,6-diaminoresorcinol dihydrochloride (D...