Copolymer of grafting maleic anhydride on molten polypropylene and preparation method for copolymer

Abstract

The invention discloses copolymer of grafting maleic anhydride on molten polypropylene and a preparation method for the copolymer. The preparation method comprises the following steps of: uniformly stirring the following raw materials in percentage by weight: 85 to 98.6 percent of polypropylene, 0.5 to 8 percent of maleic anhydride, 0.5 to 10 percent of beta-pinene, 0.2 to 3.5 percent of initiator and 0.2 to 2 percent of antioxidant; and performing melt extrusion granulation by using a stepwise heating mode. A weight ratio of the maleic anhydride to the beta-pinene in the copolymer is 1:0.5-1:20. A second comonomer of beta-pinene is introduced, the grafting rate of grafting the maleic anhydride on the polypropylene is improved, and the beta-pinene has a crosslinking function and can keep the impact strength.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a copolymer of molten polypropylene grafted with maleic anhydride and a preparation method thereof. Background technique [0002] Polypropylene plastic has become one of the most promising thermoplastic polymer materials due to its excellent mechanical properties, chemical corrosion resistance, good electrical insulation, and easy processing and molding, but it has poor strength, flammability, and poor low-temperature toughness. Many shortcomings limit its further application. Modification of polypropylene plastic is the main way to expand its application field. Polypropylene plastic is a non-polar polymer, and the fillers used for modification, such as glass fiber, flame retardants, minerals, etc., have high polarity. When the plastic is physically blended with these fillers, the two have little force. , it is necessary to add a compatibilizer to improve the compatib...

AI Technical Summary

Problems solved by technology

[0003] Polypropylene grafted maleic anhydride is a compatibilizer developed to improve the interaction between polypropylene plastics and other polar fillers. At present, traditional melt-grafted polypropylene mainly uses dicumyl peroxide as an initiator. The monomer uses maleic anhydride, the main problem is that the grafting rate of polypropylene grafted with maleic anhydride monomer is low, and there is also the addition of the second monomer styrene to increase the grafting rate of maleic anhydride monomer. During the process, under the action of the initiator, the polypropylene will partially break the chain, resulting in a significant increase in the fluidity of the material, a decrease in impact resistance, and a deterioration of the matrix performance. Therefore, a third multifunctional monomer is often added to crosslink to improve Molecular weight and impact resistance. This method is often not ideal for improving the compatibility of polypropylene plastics with other fillers and the impact of materials due to the uneven mixing of multiple monomers and the probability effect of crosslinking reactions.

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