News Details
PVC antioxidant
2018-1-14 22:56:09
PVC antioxidant
PVC plastic is one of the commonly used plastics now, the product variety is more. But some products give the impression of 'not durable'. PVC plastic raincoat, thin film, plastic sandals can be brittle or even cracked in three years. If used outdoors, life will be shorter. PVC itself has many weaknesses such as branched chain structure, double bond, at the end of the first structure (1, 2 = chloride structure link), initiator, the funds belong to impurity, structure of oxygen, allyl chloride, poly and degree, molecular weight distribution, etc., these unstable factors in the external causes (such as light, heat, oxygen, solvents, additives, and other factors, such as HCl) under the action of aging, the degradation or crosslinking, make its physical and mechanical properties worse, losing application value.
PVC resin is not very high against oxidation, which is much smaller than polyolefin. However, in some cases, it is necessary to add PVC anti-oxygen agent. In outdoor products such as agricultural film formulation, A small amount of bisphenol A can be added to slow down the degradation rate. Since the degradation process of most PVC is the process of ionization, the main antioxidant is only used when the process of free radical degradation is considered.
Because oxygen can aggravate the heat of PVC, photodegradation process, the oxidation of plasticizer at high temperature is also very fast. Oxidized plasticizer decreases the compatibility of stone and increases the "volatility". All of these destructive effects make the PVC products degrade rapidly and produce odors.
Once a double bond is formed in the process of oxidation, the subsequent oxidation process is the same as that of other unsaturated polymers. In order to prevent and alleviate the aging of PVC in the process of processing and use, the application quality of PVC products should be improved, and a certain amount of PVC anti-oxidant should be added in certain formulas.
Antioxidants are divided into two types according to their mechanism. Namely: chain termination and prevention.
Chain terminated antioxidant and free radical RO2*, R* reaction, interrupted chain growth, also known as main antioxidant. The antioxides belonging to this class have the blocked phenol class, and the secondary aromatic amine; Preventive source of antioxidants can remove free radicals, inhibit or slow led into the production of free radicals in the, also known as auxiliary antioxidant, such antioxidants including peroxide decomposition agent and metal ions, passivation agent.
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 application of more antioxidants in PVC is phosphatide and hindered phenol. The mechanism of action of two antioxidant agents is introduced.
1. Phospholipids:
Phosphatide is an auxiliary antioxidant known as hydrogen peroxidant.
The hydrogen peroxide generated by free radical chain reaction in the aging process can further induce the free radical chain reaction. Hydrogen peroxide decomposers are used to break down large molecular hydrogen peroxides and stabilize them into stable hydroxyl compounds, thus terminating the chain reaction.
Phosphite, phosphite ester is divided into liquid phosphite ester and powder phosphite phosphite ester chemical name: carbon - 4-2 different fork - - phosphate ester of fatty alcohols chelate compound polymer fluid, chemical formula C69H135O15P.
Carbon - 4-2 different fork - - phosphate ester of fatty alcohols chelate compound polymer is corresponding to A kind of high efficient auxiliary heat stabilizer, can be in high mixing, extrusion, calendering, blown film, stretch film, plastic coated, jinsu areas such as in use process to improve the color of the polymer and the processing thermal stability, the biggest characteristic of this product is environmental protection does not contain free phenol and nonylphenol, bisphenol A, main used for distribution of composite liquid calcium, zinc and composite powder calcium zinc, organic tin compound, organic rare earth, can also be used in combination with other stabilizers, main writers association with auxiliary heat stability, excellent dial from sex. This product introduces anti-ultraviolet aging and UV absorbency, so besides having excellent auxiliary thermal stability, it also has the light stability and resistance. It is an excellent chelating polymer.
2. Hindered phenols
The blocked phenols belong to the main antioxidant, the chain termination type antioxidant. In the form of action, it belongs to the hydrogen atom.
Hindered phenol molecules containing O -- - H has a lively hydrogen reaction functional group, as a result of the hydrogen transfer and the heat, light and oxygen, produce the macromolecular free radical R * and oxygen free radical ROO *, to generate a stable macromolecular, which itself into a low activity cannot spread a chain reaction of free radical Ar *, so that the chain reaction stops. The mechanism of inhibiting aging of macromolecular free radicals was illustrated with 2,6-2-2 - t - 4 - toluenol (264).
In addition, the addition of antioxidants has also inhibited and alleviated the hydrogen peroxide produced after oxidation of the plasticizer, preventing further oxidation of plasticizer.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
PVC plastic is one of the commonly used plastics now, the product variety is more. But some products give the impression of 'not durable'. PVC plastic raincoat, thin film, plastic sandals can be brittle or even cracked in three years. If used outdoors, life will be shorter. PVC itself has many weaknesses such as branched chain structure, double bond, at the end of the first structure (1, 2 = chloride structure link), initiator, the funds belong to impurity, structure of oxygen, allyl chloride, poly and degree, molecular weight distribution, etc., these unstable factors in the external causes (such as light, heat, oxygen, solvents, additives, and other factors, such as HCl) under the action of aging, the degradation or crosslinking, make its physical and mechanical properties worse, losing application value.
PVC resin is not very high against oxidation, which is much smaller than polyolefin. However, in some cases, it is necessary to add PVC anti-oxygen agent. In outdoor products such as agricultural film formulation, A small amount of bisphenol A can be added to slow down the degradation rate. Since the degradation process of most PVC is the process of ionization, the main antioxidant is only used when the process of free radical degradation is considered.
Because oxygen can aggravate the heat of PVC, photodegradation process, the oxidation of plasticizer at high temperature is also very fast. Oxidized plasticizer decreases the compatibility of stone and increases the "volatility". All of these destructive effects make the PVC products degrade rapidly and produce odors.
Once a double bond is formed in the process of oxidation, the subsequent oxidation process is the same as that of other unsaturated polymers. In order to prevent and alleviate the aging of PVC in the process of processing and use, the application quality of PVC products should be improved, and a certain amount of PVC anti-oxidant should be added in certain formulas.
Antioxidants are divided into two types according to their mechanism. Namely: chain termination and prevention.
Chain terminated antioxidant and free radical RO2*, R* reaction, interrupted chain growth, also known as main antioxidant. The antioxides belonging to this class have the blocked phenol class, and the secondary aromatic amine; Preventive source of antioxidants can remove free radicals, inhibit or slow led into the production of free radicals in the, also known as auxiliary antioxidant, such antioxidants including peroxide decomposition agent and metal ions, passivation agent.
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 application of more antioxidants in PVC is phosphatide and hindered phenol. The mechanism of action of two antioxidant agents is introduced.
1. Phospholipids:
Phosphatide is an auxiliary antioxidant known as hydrogen peroxidant.
The hydrogen peroxide generated by free radical chain reaction in the aging process can further induce the free radical chain reaction. Hydrogen peroxide decomposers are used to break down large molecular hydrogen peroxides and stabilize them into stable hydroxyl compounds, thus terminating the chain reaction.
Phosphite, phosphite ester is divided into liquid phosphite ester and powder phosphite phosphite ester chemical name: carbon - 4-2 different fork - - phosphate ester of fatty alcohols chelate compound polymer fluid, chemical formula C69H135O15P.
Carbon - 4-2 different fork - - phosphate ester of fatty alcohols chelate compound polymer is corresponding to A kind of high efficient auxiliary heat stabilizer, can be in high mixing, extrusion, calendering, blown film, stretch film, plastic coated, jinsu areas such as in use process to improve the color of the polymer and the processing thermal stability, the biggest characteristic of this product is environmental protection does not contain free phenol and nonylphenol, bisphenol A, main used for distribution of composite liquid calcium, zinc and composite powder calcium zinc, organic tin compound, organic rare earth, can also be used in combination with other stabilizers, main writers association with auxiliary heat stability, excellent dial from sex. This product introduces anti-ultraviolet aging and UV absorbency, so besides having excellent auxiliary thermal stability, it also has the light stability and resistance. It is an excellent chelating polymer.
2. Hindered phenols
The blocked phenols belong to the main antioxidant, the chain termination type antioxidant. In the form of action, it belongs to the hydrogen atom.
Hindered phenol molecules containing O -- - H has a lively hydrogen reaction functional group, as a result of the hydrogen transfer and the heat, light and oxygen, produce the macromolecular free radical R * and oxygen free radical ROO *, to generate a stable macromolecular, which itself into a low activity cannot spread a chain reaction of free radical Ar *, so that the chain reaction stops. The mechanism of inhibiting aging of macromolecular free radicals was illustrated with 2,6-2-2 - t - 4 - toluenol (264).
In addition, the addition of antioxidants has also inhibited and alleviated the hydrogen peroxide produced after oxidation of the plasticizer, preventing further oxidation of plasticizer.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
Spanish
French
Italian
Portuguese
Japanese
Korean
Arabic
Russian