Ethylene vinyl alcohol copolymer/high density polyethylene blends compatibilized through functionalization

Abstract

Abstract In order to evaluate the compatibilizing effects of isocyanate (NCO) functional groups on ethylene vinyl alcohol copolymer/high density polyethylene (EVOH/HDPE) blends, HDPE grafted with 2‐hydroxyethyl methacrylate‐isophorone diisocyanate (HDEP‐g‐HI) was prepared and blended with EVOH. The grafting was confirmed by infrared spectra, and the grafting ratio was 4.9% from elementary analysis. From the morphologies of EVOH/HDPE‐ g ‐HI blends, it was found that an improved adhesion between the two components and finer dispersions were produced as a result of chemical reactions occurring during the melt blending. The depression of melting temperature of EVOH in the 10/90 EVOH/HDPE‐ g ‐HI blend indirectly indicated increased miscibility. The tensile strength of the EVOH/HDPE‐ g ‐HI blend was much higher than that of the EVOH/HDPE blend having no adhesion at each composition, and a dramatic increase in the impact strength was produced at the 90/10 EVOH/HDPE‐ g ‐HI blend composing of the fine HDPE‐ g ‐HI dispersions.