It is easy to occur aging in the process of using the adhesive, so it is necessary to add a protective system to delay aging and avoid the rapid degradation of performance.Physical anti-aging agents are generally light blocking agents or waxes, chemical anti-aging agents include amines, phenols, esters and other compounds.Synthetic rubber in the synthetic process to add a small amount of antioxidants, and in the post-processing process to add a large number of anti-aging agent.
1、Antioxidants for synthetic rubber
Synthetic rubber in the process of adding antioxidants to the synthesis process and product color to choose.Soluble rubber needs to choose easily soluble in the solvent used in rubber synthesis of antioxidants, latex rubber needs to choose with the emulsifier used in rubber synthesis to form a stable emulsion of antioxidants, in addition, according to the color of the product choice of polluting or non-polluting antioxidants.Polybutadiene rubber (BR), styrene thermoplastic elastomer, isoprene rubber (IR) and other soluble rubber were usually used as antioxidant BHT (264), and sometimes used as phosphite antioxidant TNP (TNPP).TNP, an antioxidant, is prone to hydrolysis and is banned because the nonylphenol it produces affects reproductive health.Antioxidant BHT is relatively low in molecular weight and easy to volatilize. Foreign studies believe that its more volatile substances are harmful to the environment. Therefore, other phenolic antioxidants are commonly used to replace it.Light color latex rubber mostly USES phenolic antioxidant styrene phenol, dark color rubber mostly USES polluting amine antioxidant.Synthetic rubber antioxidants are developing towards the direction of environmental protection, large relative molecular weight, compound and multifunctional.The oxidation-induced period or oxidation-induced temperature of raw rubber can be detected by DSC method, and the antioxidant performance can also be investigated by heat-resistant oxygen aging performance.Light - colored rubber products also need to investigate the heat - resistant oxygen aging performance and anti - yellowing performance.