| abstract |
Method of forming a microporus film by casting a solution of a film-forming polymer and quenching the film in a non-solvent system quench bath wherein the polymer is preferably a nonalcohol-soluble nylon polymer and the solvent is formic acid. The contaminated non-solvent system is then regenerated by contacting it with a heterogeneous esterification catalyst in the presence of methanol to form methyl formate and then removing the methyl formate by volatilization and recycling a portion of the treated non-solvent system to the quench bath. |