Thermo-oxidative-aging-resistant polypropylene composite and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a thermo-oxidative-aging-resistant polypropylene composite and a preparation method thereof. The thermo-oxidative-aging-resistant polypropylene composite comprises the following substrate components in percentage by weight: 52-99.4% of polypropylene resin, 0-30% of filler, 0-15% of elastomer, 0.2-1% of composite main antioxidant, 0.2-1% of auxiliary antioxidant and 0.2-1% of processing assistant. By using the composition of hindered phenol and semi-hindered phenol as the main antioxidant, one of the two ortho-positions of the phenolic hydroxyl group on the benzene ring in the molecule of the semi-hindered phenol antioxidant is substituted by the tert-butyl group, and the other is substituted by the methyl group, so the steric hindrance is greatly reduced as compared with the hindered phenol antioxidant, thereby obviously enhancing the free radical trapping efficiency; and thus, the main antioxidant can ensure the material to have favorable thermo-oxidative aging resistance, and can eliminate the free radicals generated in the extreme working process, thereby ensuring the thermo-oxidative-aging resistance of the final polypropylene part.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a thermal-oxidative aging-resistant polypropylene compound and a preparation method thereof. Background technique [0002] With the rapid development of the petrochemical industry, polypropylene materials have gradually replaced traditional engineering plastics such as ABS, PC / ABS, PBT, and PA with their high cost-effective advantages, and have been widely used in automotive interior and exterior materials. [0003] In order to meet the necessary heat aging requirements for the interior and exterior of automobiles, a certain amount of heat stabilizers need to be added to the polypropylene materials for automobile interior decoration in the production process to ensure the heat aging requirements of the parts within the service life of the automobile. In the existing anti-thermal and oxidative aging technology of polypropylene, the main antioxidant is usually...

AI Technical Summary

Problems solved by technology

In the existing anti-thermal and oxidative aging technology of polypropylene, the main antioxidant is usually a symmetrical hindered phenolic antioxidant, which is due to the fact that the two ortho positions of the phenolic hydroxyl group on the benzene ring in the molecule are surrounded by tert-butyl Substituted by radicals, so its steric hindrance is very large, and it is not easy to be oxidized. It can eliminate free radicals for a long time and play a long-term role in resisting thermal and oxidative aging. However, the disadvantage is that the steric hindrance of the phenolic hydroxyl group is too large, resulting in extreme injection molding Under the process conditions, the phenolic hydroxyl group cannot quickly eliminate a large number of free radicals generated by high temperature and high shear during the injection molding process. Therefore, the traditional technology alone adding hindered phenolic antioxidants as the main antioxidant cannot efficiently eliminate the free radicals generated during the process. Free radicals, resulting in poor thermal and oxidative aging resistance of polypropylene injection parts

Moreover, during the plasticization and injection molding of polypropylene particles into parts in the injection molding machine, they will also be degraded due to the high temperature and high shear in the injection molding machine and the mold, and consume a large amount of heat stabilizers, which makes the polypropylene injection molding The thermo-oxidative aging performance of auto parts is severely reduced during subsequent use

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