Mechanical properties and thermal stability of high-temperature (cooking temperature)-resistant PP/HDPE/POE composites

Abstract

The heterogeneous nucleation process of polypropylene (PP)/high density polyethylene (HDPE)/thermoplastic elastomer (POE) composites was realized through blending modification, and characterization techniques, including scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and dynamic mechanical analysis, were used to analyze the pattern of the impact of modified dicyclohexyl-terephthalamide (TMB-5) on the mechanical properties and thermal stability of the PP/HDPE/POE composites. The results indicated that the modified TMB-5 was advantageous to the improvement of the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites. When the amount of added modified TMB-5 was 0.4%, the impact strength and tensile strength of the PP/HDPE/POE composites increased to 36.3 kJ/m2 and 31.7 MPa, respectively, which were, respectively, 99.5% and 8.5% higher than those of the materials prepared when the amount of added modified TMB was 0.1%. The materials had higher storage modulus in room-temperature and high-temperature environments: 2,438.2 MPa (room temperature), 1,103.9 MPa (120°C), and 1,054.8 MPa (140°C). In addition, the capability of the PP/HDPE/POE composites to crystallize was improved continuously, and the crystallinity increased considerably. At the same time, the crystallization and melting temperatures increased, β-crystal formation was induced, and glass transition temperature increased, thus effectively improving the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites.