Studied On The Composites Polypropylene (PP)/Wasted Coconut Shell Powder

This study, takes the grafting PP[PP-g-GMA] as the compatibilizer of wasted coconut shell powder and polypropylene (PP). And we made PP-g-GMA to increase the compatibility of coconut shell powder composite materials in the internal mixer and extruder.Through the orthogonal experiment, we research the dose of the PP-g-GMA, the dose of coconut shell powder, and processing temperature’s effects on composite materials’tensile strengh and impact. Employing the single factor experiment, we respectively studies PP-g-GMA and coconut shell powder dose range’s influence on composite materials’comprehensive mechanical properties. The results show that:the appropriate processing temperature is180℃C, the appropriate amount of PP-g-GMA and coconut shell powder are15%(coconut shell powder as a benchmark) and10%(PP as a benchmark). When the unmodified coconut shell powder’s filling mass fraction is not more than20%, coconut shell powder has a reinforcing effect on PP but when filling mass fraction is more than20%, the properties of the composite material declines (poorer than pure PP).Within the score range of acoconut shell powder filling, the tensile strength and impact strength of the PP/coconut shell powder composite materials which added compatibilizer PP-g-GMA are better than those without PP-g-GMA or pure PP’s, while its elastic modulus is lower;when the mass fraction of PP-g-GMA and coconut shell powder is15%and10%respectively, compared with pure PP, the tensile strength and impact strength of composite materials which added compatibilizer increased by30.1%and65.6%. Compared to the composite material without the compatibilizer, the tensile strength and impact strength increased by28.45%and56.9%.SEM analysis of morphological structure on material shows that the addition of PP-g-GMA improves the dispersion of the coconut shell powder in the PP matrix and the interfacial bond strength in the two-phase. The reason for the destruction of composite materials under external force is not only caused by coconut shell powder particles debonding, but mainly caused by combined action between debonding of coconut shell powder particles in the dispersed phase and the cold pull plastic deformation damage in PP matrix.DMA analysis of the material dynamic mechanical properties shows that adding coconut shell powder in PP, the rigidity and the deformation resistance capability of PP increases. And the composite materials with compatibilizer PP-g-GMA has better deformation resistance ability in low temperature. Furthermore, it also has lower Tg and higher tand values, which means better impact resistance both in high and.low temperature areas.The DSC analysis of crystallization and melting performance of the materials shows, coconut shell powder makes PP crystallization ability decreases obviously, but the addition of compatibilizers PP-g-GMA, through improving coconut shell powder particle’s dispersion, letting coconut shell powder smaller particle play its heterogeneous nucleation function, can promote PP’s heterogeneous nucleating agent to some extent.The TG/DTG analysis of material’s heat decomposition performance and MFR analysis of material processing flow performance shows that, the composite materials which added compatibilizer PP-g-GMA have excellent heat decomposition performance(compare with pure PP, and its initial temperature and half weightlessness temperature increases to50.4℃and37.5℃),and good processing flow performance.The results of this study shows that, on the premise of meeting the compound material mechanical properties, through the compatibilizer PP-g-GMA modification,we can improve the coconut shell powder’s filling quantity, to achieve high filling and lower the cost at the same time.