Modification of PP with EVA can effectively improve the impact properties, elongation at break and melt flow index (MI) of the material, and the surface gloss of the product is also improved. The vinyl acetate content of EVA is 14% ~ 18%. At this time, EVA is an amorphous material with low polarity, and it has obvious toughening effect after adding PP*** mixed system. The increase of MI is beneficial to the uniform dispersion of components in molding and * * * mixing system. Beijing Institute of Technology modified PP with EVA- 15, the highest toughness of the material is 12 times higher than that of PP, but the rigidity is not much reduced, and the cost is lower than that of elastomer or rubber modified PP 1.3 PP/PA.

The mixed modification of PP and PA*** overcomes their inherent shortcomings and makes the material have excellent comprehensive properties. Among many kinds, PP/PA6 system is the most studied at present. Zhao Shulan and others chose PA6 as the toughening agent of PP. After mixing it with PP, the impact strength increased by 49.5% compared with pure PP, and the bending strength changed little, but the tensile strength decreased by 13.8%. It can be seen that PA6 has a certain toughening effect on PP, but from the structural analysis, due to the great polarity difference, the compatibility between PA6 and PP is poor. Therefore, adding intermediates as interface improvers to improve their compatibility has become the focus of research. In this paper, maleic anhydride grafted polypropylene (PP-G-MAH) was added to binary mixtures as a compatibilizer. As a result, the impact strength of the system is increased by 1 13% compared with pure PP, the bending strength is slightly increased, and the tensile strength is only decreased by 2.7%.