Effect of Maleic Anhydride-Grafted Polypropylene as a Compatibilizer and Dynamic Vulcanization on Morphology, Rheology, Mechanical and Thermal Properties of Polypropylene/Butadiene Rubber Blend

The effect of using maleic anhydride-grafted polypropylene (MAH-g-PP) as a compatibilizer, as well as dynamic vulcanization on the morphological, mechanical, thermal, and rheological properties of polypropylene/polybutadiene rubber (PP/BR) blend, was investigated. Incorporating MAH-g-PP increased the interfacial adhesion between the PP matrix and BR droplets. This led to the reduction of BR droplets dimensions and improved impact strength, static, and dynamic mechanical properties. The inclusion of MAH-g-PP in PP/BR blends resulted in a modification of the crystallization structure of the PP matrix in the presence of BR droplets. Dynamic vulcanization increased interfacial adhesion, prevented the coalescence of rubber droplets, and enhanced mechanical properties, as evidenced by a notable 56% increase in elongation at break. Furthermore, dynamic vulcanization and the development of three-dimensional networks of vulcanized BR in the PP/BR blend reduced the mechanical loss factor (19%). The simultaneous use of the compatibilizer and dynamic vulcanization resulted in a synergistic effect and caused the mechanical properties of the sample to increase further, as shown by a considerable 70% increase in elongation at break and a 31% increase in tensile strength.