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Antagonism effect of antioxidants
2018-1-2 20:55:53
Antagonism effect of antioxidants
The antagonism of antioxidants refers to the effect of the combination of 2 or more antioxidants, which is less than the effect of their use alone. The antagonism of antioxidants is a phenomenon that an antioxidant has a harmful effect on the other antioxidants. Although the compound use of blocked phenol and sulfur containing compounds can improve thermal stability, and the use of hindered amines can improve the stability of light. However, the oxidation products of the sulfur compounds may be very acidic, and they react with the hindered amine to produce ammonium salts, making the hindered amines lose the effect of light stabilizers.
In addition, there is a antagonistic effect between the phenols and the hindered amines, but the side effects can be minimized by proper proportions. When phenol and carbon black are used together, because of the catalytic effect of carbon black on direct oxidation of phenol, the antioxidant capacity of phenol decreases, and there is also a confrontation effect between them.
The presence of transition metal titanium also reduces the oxidation induction period of the polymer, which is due to the reaction of the titanium compounds with the antioxidants during processing. First, TiCl4 react with the hydroxyl of the antioxidant to get colored titanium compounds and hydrogen chloride. Hydrogen chloride acts as a Fiedal-craft catalyst to degrade antioxidants and lose their activity.
Chirinos-Padron et al also studied other three kinds of transition metal ions Cr (III) and iron (III) and copper (II) influence on the effect of several antioxidants, found in the oven aging condition, the activity of metal ions on antioxidant promoting or antagonistic effect, this effect depends on the metal / antioxidant system. These effects are the result of the indirect interaction of the components that can delay or accelerate the decomposition of antioxidants.
When the calcium carbonate is filled to PP, the effect of the antioxidant will be greatly reduced. Hu et al. Also studied the effect of calcium carbonate and talcum powder on the stability of a series of stabilizers. Their existence reduces the thermal oxidation stability of PP. This result is caused by the adsorption of the stabilizer molecules on the surface of the filler.
Color masterbatch is made of colorant, carrier resin, dispersant, coupling agent, surface active agent and synergist. The use of color masterbatch to produce colored plastic products is a widely used method in the production of plastic products. Generally speaking, the carrier resin used in the production color masterbatch is lower than the base resin used in the production products, and the melting index is high.
Triphenyl phosphite (TPPi antioxidants, stabilizer) is mainly used in PVC, polyethylene, polypropylene, polystyrene, polyester, abs resin, epoxy resin, synthetic rubber antioxidant stabilizer, used in polyvinyl chloride (PVC) products as a chelating agent, when is given priority to with metal stabilizer, cooperate with this product can reduce the harm of metal chlorides, maintain product transparency, and inhibition of color change, is also a good chemical intermediates, with phosphorus-containing flame retardant and use, can play a role of flame retardant antioxidant, and with stable performance, light can be used for synthesis alkyd resin and polyester, main raw materials for resin, this product can also be preparing pesticide intermediates trimethyl phosphite.
The carrier resin is heated for the first time during the production of color masterbatch. When it is heated again and extruded in the production process of plastic products, the thermal degradation and mechanical degradation of carrier resin first occur, and then accelerate the aging process of coloring plastic products. Although the proportion of the carrier resin in the color masterbatch is not large in the colored plastic products, it has been heated by hot oxidation over two or more times more than two times. Therefore, the production of color masterbatch and the use of color masterbatch to produce colored plastic products must be added to antioxidants.
Antithermal oxygen aging function is the basic function of anti aging of plastic material, and the anti light aging function is to improve the function based on the basic function. In order to enhance the stability of the colored plastic products, the thermal and oxygen stability of the colored plastic products should be enhanced first.
With the addition of appropriate and appropriate antioxidant in some plastic products colored by ultraviolet absorption pigments, the light stability of the products can be doubled. Data show that in high pressure polyethylene, single chrome yellow, iron oxide red or antioxidant 2246, can improve the light stability of pressure polyethylene. When the yellow or red iron oxide and antioxidant 2246 share, LDPE light stability increased more than three times. The essential role of antioxidant 2246 in this experiment is to enhance the thermal oxidative stability of HPE. The objective performance or result is to enhance the light stability of HPE.
Antioxidants should be non-toxic or low toxic, no dust or low dust. It has no harmful effects on human body in the manufacture and application of plastic products. It is harmless to animals and plants, and has no pollution to air, soil and water system.
Of agricultural film, food packing box, children's toys, disposable infusion and other indirect or direct contact with plastic food, medicines and medical appliances and the human body, not only should be used by the U. S. Food and Drug Administration (FDA) inspection and license, allowing the antioxidant varieties or the Commission, but the dosage should be strictly the maximum permissible limit under control.
In particular, the antioxidants that have contact with food should use relatively non-toxic chemicals. The EC decree stipulates the maximum limit in the plastic material that is in contact with the food.
Along with the domestic plastic industry development and industrial structure upgrading, China's antioxidant industry should seize the opportunity to change the concepts from the expansion of the scale of extensive development to connotative development to enhance the core competitiveness, increase research investment, actively participate in international market competition, to the integration of upstream and downstream device, variety series, product customization, performance multi function, high molecular weight, composite and environment friendly development.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
The antagonism of antioxidants refers to the effect of the combination of 2 or more antioxidants, which is less than the effect of their use alone. The antagonism of antioxidants is a phenomenon that an antioxidant has a harmful effect on the other antioxidants. Although the compound use of blocked phenol and sulfur containing compounds can improve thermal stability, and the use of hindered amines can improve the stability of light. However, the oxidation products of the sulfur compounds may be very acidic, and they react with the hindered amine to produce ammonium salts, making the hindered amines lose the effect of light stabilizers.
In addition, there is a antagonistic effect between the phenols and the hindered amines, but the side effects can be minimized by proper proportions. When phenol and carbon black are used together, because of the catalytic effect of carbon black on direct oxidation of phenol, the antioxidant capacity of phenol decreases, and there is also a confrontation effect between them.
The presence of transition metal titanium also reduces the oxidation induction period of the polymer, which is due to the reaction of the titanium compounds with the antioxidants during processing. First, TiCl4 react with the hydroxyl of the antioxidant to get colored titanium compounds and hydrogen chloride. Hydrogen chloride acts as a Fiedal-craft catalyst to degrade antioxidants and lose their activity.
Chirinos-Padron et al also studied other three kinds of transition metal ions Cr (III) and iron (III) and copper (II) influence on the effect of several antioxidants, found in the oven aging condition, the activity of metal ions on antioxidant promoting or antagonistic effect, this effect depends on the metal / antioxidant system. These effects are the result of the indirect interaction of the components that can delay or accelerate the decomposition of antioxidants.
When the calcium carbonate is filled to PP, the effect of the antioxidant will be greatly reduced. Hu et al. Also studied the effect of calcium carbonate and talcum powder on the stability of a series of stabilizers. Their existence reduces the thermal oxidation stability of PP. This result is caused by the adsorption of the stabilizer molecules on the surface of the filler.
Color masterbatch is made of colorant, carrier resin, dispersant, coupling agent, surface active agent and synergist. The use of color masterbatch to produce colored plastic products is a widely used method in the production of plastic products. Generally speaking, the carrier resin used in the production color masterbatch is lower than the base resin used in the production products, and the melting index is high.
Triphenyl phosphite (TPPi antioxidants, stabilizer) is mainly used in PVC, polyethylene, polypropylene, polystyrene, polyester, abs resin, epoxy resin, synthetic rubber antioxidant stabilizer, used in polyvinyl chloride (PVC) products as a chelating agent, when is given priority to with metal stabilizer, cooperate with this product can reduce the harm of metal chlorides, maintain product transparency, and inhibition of color change, is also a good chemical intermediates, with phosphorus-containing flame retardant and use, can play a role of flame retardant antioxidant, and with stable performance, light can be used for synthesis alkyd resin and polyester, main raw materials for resin, this product can also be preparing pesticide intermediates trimethyl phosphite.
The carrier resin is heated for the first time during the production of color masterbatch. When it is heated again and extruded in the production process of plastic products, the thermal degradation and mechanical degradation of carrier resin first occur, and then accelerate the aging process of coloring plastic products. Although the proportion of the carrier resin in the color masterbatch is not large in the colored plastic products, it has been heated by hot oxidation over two or more times more than two times. Therefore, the production of color masterbatch and the use of color masterbatch to produce colored plastic products must be added to antioxidants.
Antithermal oxygen aging function is the basic function of anti aging of plastic material, and the anti light aging function is to improve the function based on the basic function. In order to enhance the stability of the colored plastic products, the thermal and oxygen stability of the colored plastic products should be enhanced first.
With the addition of appropriate and appropriate antioxidant in some plastic products colored by ultraviolet absorption pigments, the light stability of the products can be doubled. Data show that in high pressure polyethylene, single chrome yellow, iron oxide red or antioxidant 2246, can improve the light stability of pressure polyethylene. When the yellow or red iron oxide and antioxidant 2246 share, LDPE light stability increased more than three times. The essential role of antioxidant 2246 in this experiment is to enhance the thermal oxidative stability of HPE. The objective performance or result is to enhance the light stability of HPE.
Antioxidants should be non-toxic or low toxic, no dust or low dust. It has no harmful effects on human body in the manufacture and application of plastic products. It is harmless to animals and plants, and has no pollution to air, soil and water system.
Of agricultural film, food packing box, children's toys, disposable infusion and other indirect or direct contact with plastic food, medicines and medical appliances and the human body, not only should be used by the U. S. Food and Drug Administration (FDA) inspection and license, allowing the antioxidant varieties or the Commission, but the dosage should be strictly the maximum permissible limit under control.
In particular, the antioxidants that have contact with food should use relatively non-toxic chemicals. The EC decree stipulates the maximum limit in the plastic material that is in contact with the food.
Along with the domestic plastic industry development and industrial structure upgrading, China's antioxidant industry should seize the opportunity to change the concepts from the expansion of the scale of extensive development to connotative development to enhance the core competitiveness, increase research investment, actively participate in international market competition, to the integration of upstream and downstream device, variety series, product customization, performance multi function, high molecular weight, composite and environment friendly development.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
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