Modified polypropylene material with low molding shrinkage and without buckling deformation and preparation method of modified polypropylene material

Abstract

The invention discloses a modified polypropylene material and a preparation method thereof. The modified polypropylene material comprises the following ingredients by mass percentage: 50-55% of polypropylene, 25-30% of filler, 5-10% of glass fiber, 3-8% of shrinkage regulator, 3-8% of elastomer, 0.5-1% of coupling agent, 0.4-1% of dispersing agent, and 0.2-0.5% of antioxidant. The preparation method comprises the steps of mixing weighed PP (polypropylene) resin and the coupling agent in a high speed mixer, adding the other ingredients than the glass fiber for mixing for 5-10min, fusing, mixing, extruding, cooling, drying, pelleting and packaging the mixed material and the glass fiber, and obtaining the modified polypropylene material. According to the polypropylene material and the preparation method, horizontal and vertical flow shrinkages of polypropylene are reduced to below 0.8%, the difference between the shrinkages is very small (below 0.1%), the polypropylene material has excellent processability and rigidity and balanced toughness, a product made of modified polypropylene is free from warpage, no fiber exists on the surface of the product, and the application field of the polypropylene material is expanded greatly.

Description

technical field [0001] The invention relates to a modified polypropylene material with low molding shrinkage and no warping and deformation and a preparation method thereof. Background technique [0002] Polypropylene material is a polymer material with regular structure and high crystallinity. It has low density, good mechanical properties, good heat resistance, stable chemical properties and good processing and forming properties. Therefore, it is widely used in automobiles, home appliances, and construction And the field of daily life has been widely used. However, since polypropylene is a crystalline material, its molding shrinkage rate is relatively large (1.5%~2.5%). Its application is limited in some precision parts that require low shrinkage of the material and no defects in the appearance of the molding. The shrinkage rate of polypropylene can be reduced by glass fiber and mineral filling modified polypropylene material. However, usually due to the anisotropy of ...

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Problems solved by technology

[0005] At present, there is no modified polypropylene material that can ensure that the shrinkage rate in the horizontal direction and the vertical direction are small at the same time, and the difference between the two values ​​​​is small (less than 0.1%)

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