Pyrolysis Behavior of Ester Substituted Poly(p-phenylene)s and Determination of Its Microstructural Arrangement through TGA

Abstract Four 2,5-dicholorobenzoate monomers were prepared by chlorination and esterification and then polymerized to ester substituted poly( p -phenylene)s through Ni/Zn catalyzed coupling reaction. The thermal stability and pyrolysis behavior of ester substituted poly( p -phenylene)s were investigated through TGA method. The possible mechanism of thermal modification of the polymers was proposed that included de-esterification, dehydration and decarboxylation, and finally de-anhydridization. Only pyrolysis of esters substituted poly( p -phenylene)s containing two neighboring carboxyl groups may result in the formation of the corresponding anhydride.