Mechanical properties of polypropylene by diversely compatibilizing with titanate whiskers in composites

Isotactic polypropylene (PP)/titanate whisker composites were tailored by two component blends, in which PP and the titanate fillers were processed with maleic anhydride-grafted polypropylene (PP-g-MAH) and maleic anhydride-grafted polyethylene (PE-g-MAH) as compatibilizing agents, respectively. The whiskers modified with silica and 3-aminopropyl triethoxysilane ensured the hybrid interfacial conceivement, and the usages of the diverse compatibilizers were intended for toughening effect and balanced mechanical properties of PP. Positively compatible PP-g-MAH and anti-compatible PE-g-MAH endowed the composites of PP/titanate whiskers with remarkable rise in notch impact strength of 7.4 ± 0.1 kJ/m2, which was significantly higher than 3.1 ± 0.4 kJ/m2 for PP with trivial deterioration to both tensile and flexural strengths. Differential scanning calorimetry results demonstrated the presence of β-form crystals in the composite, favoring the extra improvement of impact toughness. Variations of glass transition temperature and storage energy detected by dynamic mechanical analysis also revealed both of the compatibilizing agents worked in the composites for reinforcement. With the greatly improved tenacity as well as balanced tensile and flexural properties in the composite, PP could find its potentials as impact plastic materials.