A kind of graphene-based antioxidant and its preparation method and application

Abstract

The invention relates to the field of polymer composite materials, in particular to a graphene-based antioxidant and its preparation method and application. The invention provides a preparation method of a graphene-based antioxidant. The preparation method is as follows: firstly, graphene oxide is subjected to the action of a solvent and a carboxyl activator to obtain carboxyl-activated graphene oxide, and then the antioxidant is grafted to the obtained carboxyl-activated graphene oxide, and finally filtered, washed and dried to obtain a graphene-based antioxidant. The polyolefin-based composite material obtained by adding the graphene-based antioxidant obtained in the present invention to the polyolefin matrix has the characteristics of long oxidation induction period, high initial degradation temperature and resistance to solvent extraction.

Description

technical field [0001] The invention relates to the field of polymer composite materials, in particular to a graphene-based antioxidant and its preparation method and application. Background technique [0002] Polyolefin materials are often affected by light, oxygen, and heat during processing and use, causing aging and degradation, which affects the use effect and service life. Therefore, stabilizing additives are often added in the processing and production of polyolefin materials to delay its aging and increase its thermal oxygen and light oxygen stability. Stabilizing additives are mainly divided into three categories: light stabilizers, heat stabilizers and antioxidants. Among them, the most effective and widely used method in industry is to add antioxidants to polyolefin materials. Among them, the primary antioxidant can terminate the transmission and growth of free radical chains in the oxidation process, and the secondary antioxidant can delay the generation of free...

AI Technical Summary

Problems solved by technology

[0004] Increasing the molecular weight can only solve the problem of volatilization and migration of small molecule antioxidants to a certain extent; while the inventions of existing physical adsorption and chemical grafting antioxidants can only anchor antioxidants and limit their migration and volatilization. Single effect, there is no synergistic effect between the antioxidant and the nanomaterial that fixes it; and the current adsorption and grafting methods basically need to use bridging substances as media to link the antioxidant to the nanomaterial, the steps are cumbersome and complicated, and the reaction There are many kinds of reagents and high cost; or lack of systematic comparative experiments, it is difficult to intuitively compare the anti-oxidation effect obtained before and after grafting, the anti-migration effect and extraction effect achieved after grafting

For example, the document "Gao, X., et al., Polymer Degradation & Stability, 2008.93 (8): p.1467-1471" uses a silane coupling agent to graft the modified antioxidant onto the nano-silica particles, which improves the The thermo-oxidative stability of polypropylene (PP), but the nano-silica particles themselves have no anti-aging performance, and the grafting effect is single; and this method needs to modify nano-silica and antioxidant at the same time, and the process is complicated and cumbersome

Another example is that in the patent CN105504453A, the antioxidant is activated with ethylenediamine, then grafted onto graphene oxide, and then coated with polydopamine to obtain the grafted product as a filler to ensure the thermal oxygen stability and insulation of the polyolefin composite material. performance, but the invention has used various reagents such as ethylenediamine, dicyclohexylcarbodiimide, 4-dimethylaminopyridine, dopamine, etc., the reaction cycle is long, the operation requirements are high, and it is difficult; and no modified filler anti-corrosion Characterization of migration ability

Another example is that in the patent CN106867031A, a mercapto coupling agent is used to modify graphene oxide, and then grafted with an antioxidant under the action of a catalyst. The disadvantage is that a large amount of mercapto coupling agents are needed for bridging in the process, and graphite oxide needs to be adjusted. pH of olefin dispersion

Graphene-based materials have outstanding advantages in improving the anti-aging of polymers, such as the literature "Yang, J., et al., Carbon, 2015.89 (5): p.340-349." PP, antioxidant AO, Thermally reduced graphene oxide TrGO prepared composite materials by physical blending, and obtained a good thermo-oxidative stabilization effect; but the disadvantage is that the anti-thermal-oxidative degradation ability is not improved enough, and the migration and extraction of antioxidants are not characterized.

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