Improving the anti-environmental stress cracking performance of amorphous polymer through volume pulsation injection molding with semi-crystalline polymer

Abstract

Failures caused by environmental stress cracking (ESC) in polymers, especially amorphous ones, pose substantial concerns for their safety issues and long-term applications. Herein, we proposed a strategy through volume pulsation injection molding (VPIM) to delay the cracking by extending the solvent diffusion path and modulating the crystallization behavior of semi-crystalline polymers. High-impact polystyrene (HIPS) was employed as a model material with high-density polyethylene (HDPE) as the ESC resistor. The as-prepared blend after the VPIM treatment can suffer 48 h of loaded oil immersion, which can be hardly achieved for reference samples prepared via the conventional injection molding (CIM) method and pure HIPS. Through in-depth investigations of the oil-stress treatment-induced ESC behaviors, we demonstrated the improvement in the anti-ESC performance can be attributed to the in-situ fiberization of HDPE during VPIM. This work will open new possibilities for improving the anti-ESC performance of polymers in practical applications.