Highly Tough and Thermally Stable Polylactide Blends Compatibilized with Glycidyl Methacrylate‐Grafted Polypropylene

To attain eco‐friendly and sustainable polylactide (PLA) materials possessing highly enhanced toughness, thermal stability, and processability without significant loss in elastic modulus, for the first time, PLA‐dominant blends with 1–30 wt% glycidyl methacrylate‐grafted polypropylene (PPGMA) loadings are fabricated via an efficient masterbatch melt‐compounding process. For the purpose, PPGMA is fabricated via in situ grafting reaction of PP with GMA and styrene. The scanning electron microscope images reveal that PLA/PPGMA blends do not show recognizable phase‐separated domains, unlike immiscible PLA/PP blends. The Fourier‐transform infrared spectroscopic and melt‐rheological analyses support the presence of specific interactions between PLA and PPGMA as well as the compatibilizing effect of PPGMA‐g‐PLA formed during the melt‐compounding. The thermal analyses demonstrate that PPGMA component accelerates the crystallization of PLA in the blends and that the thermal decomposition temperatures of PLA/PPGMA blends are higher than those of neat PLA and PPGMA components. The dynamic mechanical analysis shows that a maximum storage modulus is attained for PLA‐dominant blend with 30 wt% PPGMA. Noticeably, the impact strength (≈305.6 J m−1) of PLA‐dominant blend with only 5 wt% PPGMA loading is almost three times higher than that (≈111.6 J m−1) of neat PLA and it is very comparable to the value (≈316.9 J m−1) of neat PP. Glycidyl methacrylate‐grafted polypropylene (PPGMA) is fabricated by in situ grafting reaction of PP with GMA and styrene during melt‐compounding. Polylactide (PLA)/PPGMA blends are manufactured via efficient masterbatch melt‐compounding. There exist specific interactions and in situ grafting reactions between PLA and PPGMA. PLA/PPGMA blends do not show phase‐separated domains, unlike PPG/PP blends. PLA/PPGMA blends have highly improved toughness and thermal stability.