The effective solution to the yellowing of elastomers is to add antioxidants and ultraviolet absorbers, which can effectively prevent and delay the yellowing. However, there are many kinds of antioxidants, and the selection of suitable products requires certain technical support and experience accumulation.
The main culprit of oxidative yellowing of elastomers is ultraviolet rays, which are mainly from sunlight. Therefore, especially in the face of customers whose products need to be used outdoors, we will recommend adding a certain amount of ultraviolet absorbers to the products. , Can effectively absorb ultraviolet rays and delay yellowing. Moreover, the use of ultraviolet rays and antioxidants together can play a synergistic effect, and the effect of 1 plus 1 is greater than 2.
2. What are the different classifications and mechanisms of antioxidants?
The classification of antioxidants, one is the main antioxidant: capture peroxidative free radicals, mainly hindered phenol antioxidants; the main anti-sterically hindered phenols, antioxidants 1010,belong to this category, by capturing the process of plastic degradation. Generated free radicals and long-term sustained anti-oxidative effect
One is auxiliary antioxidant: decompose hydroperoxides, mainly phosphites and thioesters. Auxiliary anti-phosphites and thiolipids, 168 belongs to phosphite auxiliary anti-oxidants, which can achieve anti-oxidation by decomposing the peroxides generated by the further degradation of plastics, mainly providing thermal processing stability; Anti-co-use can produce synergistic effects (simple analogy: 1+1>2)
In general, according to the production process of each manufacturer, raw materials, solvents, additives, fillers, which stage of yellowing, and the degree of yellowing are different, it is recommended to use different antioxidants.
3. What is the difference between Antioxidant 1010 and 1076?
As a hindered phenolic antioxidant, the effective functional group of 1010 is four times that of 1076, which means high efficacy. The usage mainly considers the compatibility with the resin in the later stage and the processing situation.
1010: Properties: Scientific name [?-(3,5 di-tert-butyl 4-hydroxy-phenyl) propionic acid] pentaerythritol ester. White crystal powder. Melting point 119 ~ 122 ?. No change, no pollution, heat aging, washable, and not volatile. Widely used in thermal processing of polypropylene, polyethylene, polyoxymethylene, ABS resin, etc. Can prolong the service life of plastic products. After preparing methyl 4-hydroxy-3,5-tert-butylphenyl propionate from phenol, it is synthesized with pentabenol in the presence of sodium methoxide catalyst.
1076: Nature: Scientific name ?-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate. White crystal powder. Odorless and non-toxic. Melting point 50 ~ 55 ?. No pollution, no discoloration, low volatility and good thermal stability. Good miscibility with most polymers. Insoluble in water, soluble in many organic solvents. For polypropylene, polyethylene, polystyrene, polyvinyl chloride, ABS resin, polyamide, polyester, etc. It is prepared by esterification with octadecanol after 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid is generated by the action of phenol and isobutylene.
Antioxidant 1010 is a white crystalline powder with stable chemical properties. It can be widely used in general plastics, engineering plastics, synthetic rubber, fibers, hot melt adhesives, resins, oils, inks, coatings and other industries.
Antioxidant 168 is an auxiliary antioxidant, which is compounded with the main antioxidant zm-1010 or 1076, and has a good synergistic effect, which can effectively prevent the thermal degradation of polypropylene and polyethylene in the basic injection molding, and give the polymer additional long-lasting protection.
This product is non-coloring, non-polluting, and has good volatility resistance. For polyethylene, polypropylene, polystyrene, polyester and polyamide and other products. Widely used in polyolefins, styrene monomers and copolymers, elastomers, adhesives, engineering plastics (such as: PE, PP, PVC, PS, polyamide, polycarbonate, ABS) and other polymer materials
Antioxidant 1076 is used together with antioxidants SONOX 168 and DLTDP, which has a significant synergistic effect and can effectively inhibit the thermal degradation and oxidative degradation of polymers. This product is widely used in polyethylene, polypropylene, polyoxymethylene, ABS resin, polystyrene , polyvinyl chloride alcohol, engineering plastics, synthetic rubber and petroleum products, the general dosage is 0.1% to 0.5%.