A PROCESS FOR A TWO STAGE MELT POLYMERIZATION FOR THE PRODUCTION OF POLYBENZIMIDAZOLE

摘要

The invention is a two-step process for the production of high molecular weight polybenzimidazole. Step one comprising: combining at least one aromatic hydrocarbon tetraamine and a dicarboxylic component; heating the reactants under agitation; terminating agitation while continuing heating to a step one temperature of about 230 °C and allowing the reaction mass to foam; cooling the reaction mass to a friable foamed mass; crushing said mass to obtain a first pulverized prepolymer. Step two comprising: transferring said first prepolymer into a second reaction vessel; pressure washing of the first reaction vessel to obtain a second pulverized prepolymer; transferring the second ground prepolymer to the second reaction vessel; heating the first and second pulverized prepolymers under agitation to a temperature that is higher than step one temperature until the desired degree of polymerization is achieved.