Synergistic action of amphiphilic polyacrylate-based sizing and β-nucleating agents for enhancing mechanical properties of short glass fiber reinforced polypropylene composites

The attainment of both high mechanical strength and good toughness has always been the ultimate goal for developing viable fiber-reinforced thermoplastic composites for critical structural applications in the aerospace and automobile fields. Most sized glass fiber reinforced polypropylene composites exhibit higher tensile and flexural strengths but lower impact resistance than commercial glass fiber reinforced polypropylene composites, which limits their future utilization in industry. In this work, an amphiphilic sizing agent as the interfacial modifier and a β-nucleating agent as the added toughener were simultaneously used to improve the mechanical properties of short glass fiber reinforced polypropylene composites and addition of a β-nucleating agent improved the impact resistance of the sized glass fiber reinforced polypropylene composite without degrading the tensile and flexural strengths. Additionally, polarized light microscope and differential scanning calorimetry demonstrated that the improved mechanical properties of the composites were attributed to the improved compatibility between glass fibers and polypropylene and the enhanced crystallization ability of polypropylene. Thus, the proposed method provides a way to balance the strength and toughness of composites.