Caco < Sub > 3 < / Sub > / Elastomer/hdpe/pp Composite Material Performance Research

Polypropylene (PP), as a general plastic, is widely used in machinery, instruments, automotive and packaging industries due to its comprehensive properties. However, the development of PP composites is restricted by its brittleness. Addition of thermoplastics, elastomers and rubber can be considered as economical and effective methods to extend its industrial applications. The toughness of polypropylene (PP) increases with the addition of thermoplastics, elastomers and rubber, however the stiffness and melt low properties of PP composite decreases significantly. Therefore, balancing their ratio is a challenging task.The HDPE/PP composites were prepared by a twin screw extruder and injection molding, and analyzed by DSC, SEM and mechanical testing. Appropriate HDPE content can improve the impact strength, melt processability, tensile properties, flexural properties and crystallization of PP. Compared with pure PP, the average impact strength, tensile strength, flexural strength, tensile modulus of the HDPE/PP (12/88) composites increase by40.1%、15.8%、27.5%and20.0%, respectively. However, with further increaseing HDPE content, the comprehensive properties of HDPE/PP composite decreases significantly due to the incompatibility between HDPE and PP matrix.The elastomer/HDPE/PP ternary blends were prepared by melt compounding using a twin screw extruder, and analyzed by means of SEM, DSC. The effects of elastomer content and types (EPDM, SBS and POE) on mechanical properties, melt processability and morphology of HDPE/PP (12/88) composites were investigated. The results demonstrate that POE has good miscibility with HDPE/PP(12/88)composites and result in a finer dispersion of POE in HDPE/PP matrix, compared with EPDM and SBS. POE can enhance the crystal formation of PP in the composites, and effectively improve the impact strength and other mechamical properities of HDPE/PP (12/88) composite. Compared with mechamical properities of HDPE/PP (12/88) composite, the average impact strength, tensile modulus, flexural strength of the POE/HDPE/PP(8/12/88)composites increase by5times,16.7%,2.2%, respectively.Incorporation of8wt%nano-CaCO3content results in improvement of impact strength, tensile and flexural strength of POE/HDPE/PP (8/12/88) composites, and can promote crystallization of PP due to a finer dispersion of nano-CaCO3in composites. However, the higher loading of nano-CaCO3tended to hamper crystal growth and decrease the impact strength, tensile strength, flexural strength, tensile modulus of the composites. The better comprehensive properties were obtained for the PP composites with8wt%nano-CaCO3,7.4wt%POE and10.2wt%HDPE.