A super‐toughened nylon 12 blends via anionic ring‐opening polymerization of lauryllactam in a twin screw extruder. Preparation, morphology, and mechanical properties

Abstract Nylon 12 blends (BP) with nitrile‐butadiene ultrafine full‐vulcanized powdered rubber (NBUFPR) were successfully synthesized in a corotating intermeshing twin screw extruder via anionic ring‐opening polymerization of lauryllactam at 250°C. The in situ formed blends were characterized by mechanical test, fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. A brittle‐tough transition occurs when NBUFPR content is 4 wt%. And the notched Izod impact strength achieves 989 J m −1 when 5 wt% NBUFPR was added. Because of the good dispersion property of NBUFPR during the process ofreactive extrusion, the interparticle distance decrease remarkably. Besides, the in situ formed NBUFPR‐ graft ‐PA12 leads to better adhesion between the two phases. For comparison, another series of blends (BL) were also prepared by melt blending hydrolytic‐polymeric PA12 and NBUFPR in the same twin screw extruder. Brittle‐tough transition did not appear in BL blends within the same range of NBUFPR content. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers