Abstract: A polyamide precursor of a polybenzazole polymer is prepared by reacting an aromatic bis(alkenyl)ester with a ring forming, aromatic diamine. The precursor can be prepared in an organic solvent for the monomers to form a soluble polyamide precursor which can be subsequently cyclocondensed to form a PBX polymer. A polybenzoxazole precursor is prepared by the reaction of a bis(alkenyl)ester and a bis(ortho-hydroxyamine). A polybenzazole polymer is easily prepared by heating the polyamide, PBX precursor.

Abstract: A process for preparing polymers comprising pendant ketone functional moieties, the steps of the process comprising exposing a mixture comprising an ethylenically unsaturated addition polymerizable monomer and a .beta.-substituted ketone compound corresponding to the formula:XCH.sub.2 --CHR'--C(O)RwhereX is a suitable leaving group,R' is hydrogen or R; andR is alkyl or aryl of up to 12 carbonsto vinyl ketone monomer formation conditions to prepare the corresponding vinyl ketone monomer from the .beta.-substituted ketone compound and subsequently exposing the mixture to addition polymerization conditions to prepare the resulting polymer.

Abstract: High molecular weight polymers of vinyl aromatic monomers are prepared by free radical polymerization in the presence of 5 to 5000 ppm of a soluble organic acid having pKa from 0.5 to 2.5.