N-alkyl pyrrolidones as innovative PVC plasticisers

Abstract

It has been found that N-alkyl (C₈ to C₁₈) pyrrolidones are highly efficient, strong solvating performance plasticisers which decrease gelling temperatures substantially. Higher alkyl pyrrolidones also exhibit very low volatility. Solubility temperatures (DIN 53408) are between 52°C (N-octyl pyrrolidone) and 80°C (N-octadecyl pyrrolidone). Plasticising efficiency tests using comparative of Shore A values showed that N-alkyl pyrrolidones are up to 40% more efficient than the standard plasticiser diisononylphthalate. Cold flexibility as assessed by the folding test DIN EN495-5 and impact test DIN 53372 found sample failure to begin in the temperature range from −55 to −65°C. Further trials in filled systems showed that N-alkyl pyrrolidones are highly compatible with calcium carbonate and allow very high filler loads. Manufacturing tests with a highly filled system using an extruder resulted in increased output while significantly reducing plasticiser levels and processing temperatures, and thus reducing energy requirements.