The Influence of Maleic Anhydride-Grafted Polymers as Compatibilizer on the Properties of Polypropylene and Cyclic Natural Rubber Blends

Polypropylene (PP) is a polyolefin material. This thermoplastic polymer has a linear structure composed of repeating units of hydrogen and carbon atoms. PP has the advantages of versatility, easy formulation and low cost. But despite its resistance, PP is still susceptible to oxidative stress, which may affect its mechanical properties. Therefore, expanding the application of polypropylene through blending technology has become a research hotspot.

In this paper, a compatibilizer is added to the blending system to mix polypropylene/recycled natural rubber (PP/CNR). The main challenge is how to compatible these two materials with obvious saturated and non-polar structural characteristics. As an affinity agent, the copolymer of maleic anhydride grafted polypropylene and maleic anhydride grafted cyclic natural rubber is combined with PP/CNR (80/20wt.%) blend. Scanning electron microscope (SEM) was used to analyze the influence of these compatibilizers, which showed that the PP matrix was homogeneous, indicating that CNR was uniformly dispersed in the PP matrix. The thermogravimetric method (TGA) analysis confirmed that the addition of compatibilizer improved the thermal stability of the blend. The differential scanning calorimetry (DSC) curve shows that the glass transition temperature (Tg) is significantly reduced, which means that the incorporation of maleic anhydride grafted, the compatibility has been greatly improved, thereby improving the comprehensive mechanical properties.

Fig.1 Concentration of maleic anhydride grafted polymer and tensile strength (a), concentration of maleic anhydride grafted polymer and Young's modulus (b), concentration of maleic anhydride grafted polymer and elongation at break (c) )