A kind of polypropylene composite material and its preparation method and application

Abstract

The invention discloses a polypropylene composite material with high gloss, high bending modulus and low shrinkage, a preparation method and application thereof. The material comprises the following components by weight: 5-35 parts of the first polypropylene, 10-75 parts of the second polypropylene, 5-15 parts of compatibilizer, 5-35 parts of polystyrene, and 10-30 parts of glass fiber , 3-20 parts of maleic anhydride grafted polypropylene, 0.1-2 parts of coupling agent, and 0.1-0.5 part of antioxidant; wherein, the melt index of the first polypropylene is higher than that of the second polypropylene. The invention realizes the balance of the mechanical strength, luster and dimensional stability of the polypropylene composite material through the unique fluidity adjustment and glass fiber distribution adjustment process, and adopts a two-step method. The material has high flexural modulus, high notched impact strength, low shrinkage, high gloss, good processing fluidity, and low cost. It can replace ABS and be used in various home appliances, automobiles, toys and other injection molding products.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and particularly relates to a polypropylene (PP) composite material and a preparation method and application thereof. Background technique [0002] ABS material is a general-purpose thermoplastic material with excellent performance. It has high surface gloss, high flexural modulus and excellent impact toughness performance. It is widely used in surface and shell parts of home appliances. However, compared with general-purpose plastics such as polypropylene (PP), polyethylene (PE), and polystyrene (PS), ABS materials have higher prices, lower heat distortion temperatures and poor weather resistance, so people have been trying to modify them. PP and other general-purpose plastics replace ABS materials. [0003] Among the commonly used general-purpose plastics, PP materials have light specific gravity, excellent heat resistance, good bending fatigue resistance, and low prices, and are wid...

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Problems solved by technology

Chinese patent document CN101768312B discloses a material with high gloss and high impact strength made of PS, but the material has low heat resistance, the heat distortion temperature is only 75°C, and the flexural modulus is relatively low, the highest is only 2100MPa

CN102250413B also discloses a method for preparing high-gloss high flexural modulus PP by using PS reinforced PP. This method uses PS to increase the flexural modulus of PP, and the prepared product has high gloss and low shrinkage, and can replace ABS in many places; But the notched impact strength of the product is only 4KJ / m 2 , which limits its application in some products that require high toughness, such as children's toys

In order to further reduce the cost increase caused by the introduction of low-shrinkage PP, CN109517272A discloses another method for preparing PP with high flexural modulus, wherein the low-density PP replacing ABS is composed of the following raw materials in weight percent: PP resin 52.5- 63%, toughening agent 15-20%, talcum powder 18-20%, whiskers 3-6%, additives 1-1.5%; however, although the introduction of talc powder in this system can improve the flexural modulus, the material The gloss is also greatly reduced, which is not suitable for the preparation of PP composite materials with high gloss and high flexural modulus.

[0008] To sum up, there is currently no PP composite material with high flexural modulus, high gloss, low shrinkage rate and price advantage that can better replace ABS materials.

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