Abstract:Automotive polypropylene (PP) is susceptible to scratches, which cause appearance and performance loss during use. Studying the factors affecting PP scratch resistance and improving PP scratch resistance are important prerequisite for the market demand of scratch-resistant PP for vehicles. Using PP as substrate, the effects of four kinds of scratch-resistant agents with different action mechanisms (erucamide, silicone masterbatch, talc powder and polysiloxane) on mechanical properties, crystallization properties and scratch resistance of PP were investigated. The morphology of the scraped surface of the material was observed by polarizing microscope and ultra-depth-of-field three-dimensional microscope. The results showed that four kinds of scratch-resistant agents significantly improved the impact strength or bending strength of some PP materials, but the tensile strength decreased slightly. Erucamide, silicone masterbatch and polysiloxane did not change the crystallization morphology and crystallization behavior of PP, while talc destroyed the crystallization properties of PP. Four kinds of scratch-resistant agents all reduced the friction coefficient and color difference of PP (ΔL) and improved its scratch resistance, among which polysiloxane could not only improve the scratch resistance of PP, reduce its ΔL by about 89%, but effectively inhibit the precipitation, stickiness and whitening of PP.