Polylactide Toughening with Epoxy-Functionalized Grafted Acrylonitrile-Butadiene-Styrene Particles

Glycidyl methacrylate functionalized acrylonitrile-butadiene-styrene (ABS-g-GMA) particles were prepared and used to toughen polylactide (PLA). The characteristic absorption at 1728 cm(-1) of the Fourier transform infrared spectra indicated that glycidyl methacrylate (GMA) was grafted onto the polybutadiene phase of acrylonitrile-butadiene-styrene (ABS). Chemical reactions analysis indicated that compatibilization and crosslinking reactions took place simultaneously between the epoxy groups of ABS-g-GMA and the end carboxyl or hydroxyl groups of PLA and that the increase of GMA content improved the reaction degree. Scanning electron microscopy results showed that 1 wt % GMA was sufficient to satisfy the compatibilization and that ABS-g-GMA particles with 1 wt % GMA dispersed in PLA uniformly. A further increase of GMA content induced the agglomeration of ABS-g-GMA particles because of crosslinking reactions. Dynamic mechanical analysis testing showed that the miscibility between PLA and ABS improved with the introduction of GMA onto ABS particles because of compatibilization reactions. The storage modulus decreased for the PLA blends with increasing GMA content. The decrease in the storage modulus was due to the chemical reactions in the PLA/ABS-g-GMA blends, which improved the viscosity and decreased the crystallization of PLA. A notched impact strength of 540 J/m was achieved for the PLA/ABS-g-GMA blend with 1 wt % GMA, which was 27 times than the impact strength of pure PLA, and a further increase in the GMA content in the ABS-g-GMA particles was not beneficial to the toughness improvement. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122:2992-2999, 2011