Toughened Polyoxymethylene by Polyolefin Elastomer and Glycidyl Methacrylate Grafted High-Density Polyethylene

Ternary blends of polyoxymethylene (POM), polyolefin elastomer (POE), and glycidyl methacrylate grafted high density polyethylene (GMA-g-HDPE) with various component ratios were studied for their mechanical and thermal properties. The size of POE dispersed phase increased with increasing the elastomer content due to the observed agglomeration. The notched impact strength demonstrated a parabolic tendency with increasing the elastomer content and reached the peak value of 10.81 kJ/m(2) when the elastomer addition was 7.5 wt%. The disappearance of epoxy functional groups in the POM/POE/GMA-g-HDPE blends indicated that GMA-g-HDPE reacted with the terminal hydroxyl groups of POM and formed a new graft copolymer. Higher thermal stability was observed in the modified POM. Both storage modulus and loss modulus decreased from dynamic mechanical analysis tests while the loss factor increased with increasing the elastomer content. GMA-g-HDPE showed good compatibility between the POM matrix and the POE dispersed phase due to the reactive compatibilization of the epoxy groups of GMA and the terminal hydroxyl groups of POM. A POM/POE blend without compatibilizer was researched for comparison, it was found that the properties of P-7.5(POM/POE 92.5 wt%/7.5 wt%) were worse than those of the blend with the GMA-g-HDPE compatibilizer. (C) 2017 Society of Plastics Engineers