Direct injection molding chemical micro-foaming polypropylene composite material and preparation method thereof

Abstract

The invention provides a direct injection molding chemical micro-foaming polypropylene composite material and a preparation method thereof. The composite material is prepared by the steps of mixing a polypropylene composite material and a sodium bicarbonate foaming agent according to a certain compounding ratio and performing injection molding and forming by twice-open molding technique, wherein the polypropylene composite material is prepared from the following components in parts by weight: copolymerized polypropylene (PP) 55-65 parts, high density polyethylene (HDPE) 10-20 parts, ultra-high molecular weight polyethylene (UHMWPE) 5-10 parts, talc powder 15-20 parts, an antioxidant 0.2-0.4 parts, a lubricant 0.5-1 parts, a light stabilizer 0.5-1 parts, and other assistant 0-1 parts. Through a proper compounding ratio of PP, HDPE and UHMWPE, the molecular weights in the composite system are reasonably distributed, the molecular chains are entwisted with each other, the chain segments of different molecular weights are disorderly entwisted to form a three-dimensional reticular network structure and achieve excellent compatibility, thereby improving the molten mass strength of linear polypropylene and obtaining the micro-foaming material with small and fine pores. The composite material provided by the invention has low cost and excellent mechanical properties, is convenient in operation, achieves good weight reduction effect, effectively reduces the weight of workpieces, and realizes light weight of parts.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, in particular to a chemical micro-foaming polypropylene composite material capable of direct injection molding and a preparation method thereof. Background technique [0002] China is the world's largest car producer and market, but the rapid growth of the number of cars has brought serious problems, especially pollution, the culprit of which is car exhaust. The self-weight of the car directly affects the fuel consumption. Studies have shown that every 10% reduction in the self-weight of the car can reduce the fuel consumption by 5%. On the premise of ensuring the performance and quality of the car, reducing the weight of the car body, thereby reducing fuel consumption, has become a research topic that car manufacturers are eager to study, which is called "vehicle lightweight technology". Due to its unique microporous structure, micro-foaming materials have the advantages of light weig...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that the melt strength of linear polypropylene drops sharply above the melting temperature, the cells generated by decomposition during the foaming process are easy to merge, which severely limits the industrial application of polypropylene chemical micro-foaming, and also solves the problem of polypropylene molecular weight and ultra-high molarity. The quality of polyethylene varies too much and is incompatible with each other. The molecular weight of polypropylene cannot enter the PE segment and cannot be entangled with the molecular chain of ultra-high molar mass polyethylene, which limits the application of polypropylene in new fields.

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