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Polylactide (PLA) was melt blended with either polypropylene (PP) or a polypropylene based elastomer (PBE, Vistamaxx) in an effort to improve its mechanical properties. An ethylene−glycidyl methacrylate−methyl acrylate terpolymer (PEGMMA, Lotader) was utilized as compatibilizer through coupling to the end groups of PLA. Graft copolymers formed enhanced the adhesion between PLA and polyolefin phases and lowered the interfacial tension. The morphological, mechanical, and rheological properties of the PLA/polyolefin compatibilized blends were investigated, and the blends exhibited substantial improvement in elongation at break and tensile toughness as compared to the corresponding binary blends. The remarkable efficacy of PEGMMA as a reactive compatibilizing agent allows the bridging of two immiscible but important classes of thermoplastics, polylactide and polypropylene, and the production of ductile PLA/PP blend materials.

Low molar mass (3−17 kg/mol) amino-telechelic polyethylene (ATPE) was used to reactively compatibilize poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) via ester aminolysis of PET. A tertbutyloxycarbonyl (Boc)-protected polyethylene precursor was thermolytically deprotected during the melt-blending process to render the reactive amine termini. Spectroscopic analysis of a model reaction confirmed the presence of amide functionality in the resultant material. Through blending studies, we found that low loadings of ATPE (0.5 wt %) significantly reduced the volume of the dispersed HDPE phase particles by a factor of 8 when compared to a binary PET/HDPE blend as assessed by scanning electron microscopy (SEM). Mechanical analysis of the ATPE-compatibilized blends showed a 12fold increase in the elongation at break over the unmodified PET/HDPE blend. Ultimately, the results here offer a new approach to reactively compatibilize and toughen PET/HDPE blends and open the door for other uses of amino-telechelic polyethylene.