News Details
Antioxidant structure
2018-1-3 12:03:21
Antioxidant structure
The antioxidant structure determines its anti oxygen performance. The structure of the main antioxidant has a great relationship with its oxygen resistance.
It is known from the oxidation mechanism that the structure of a good antioxidant should have the following properties:
1, with a lively hydrogen atom, it should be more active than the active hydrogen atom on the polymer chain.
2, the free radicals of the antioxidant should have sufficient stability and can not lead to a new free radical reaction.
3, the antioxidants themselves should be more difficult to oxidize, otherwise they are oxidized.
Action mechanism of antioxidant
1. Stability of polymers using a broken chain antioxidant
The mechanism of reactive species reaction of antioxidants in intervention chain, namely, segment chain donor mechanism (CB-D) and segment chain receptor mechanism (CB-A).
The typical CB-D mechanism is the free radicals of peroxidation and the inhibitors such as phenols, followed by the reaction between aromatic amines. The free radical produced from the inhibitor AH can eliminate a peroxidase group PO2 as the reaction formula.
2. Stability of polymer using pre antioxidant
Preventive or auxiliary antioxidants can decompose hydroperoxide but do not form free radical intermediates. Therefore, they prevent the decomposition of hydrogen peroxide from free radicals to chain branching.
3. Synergism between antioxidants
A famous example is the application of cinnamoyl thiocarbamate (DLTDP) or double stearyl thiocarbamate (DSTDP) and sterically hindered phenol in some polymers' thermal stability. Another important example of synergy is the synergistic effect of sterically hindered phenol and phosphite on improving the stability of polyolefin melt.
Triphenyl phosphite (antioxidant, stabilizer TPPi) production process
1. Phosphorus oxychloride as the direct method (also called thermal method) phenol with pyridine and anhydrous benzene as solvent, in no more than 10 ℃ temperature, slowly add oxygen phosphorus chloride, then under reflux temperature, the reaction of 3 ~ 4 h. After cooling to room temperature, the reactants are washed by water to recycle pyridine. After centrifugal dehydration, the reagents are dehydrated with dried sodium sulfate, which is filtered to remove sodium sulfate. The first atmospheric distillation recovery of benzene, vacuum distillation, collected 243 ~ 245 ℃ (1.47 kPa) fraction, by cooling, crystallization, crushing is the finished product.
2. After phenol melting, stirring under add phosphorus trichloride under 25 ℃, Triphenyl phosphite is generated; Then heat up to 70 ℃ ventilation with chlorine gas, generated two chlorinated triphenyl phosphate; Again at 50 ℃ water hydrolysis, triphenyl phosphate. The hydrolysate with 5% soda solution for neutralization, water washing, the evaporation and vacuum distillation, collected 243 ~ 245 ℃ (1.47 kPa) fractions, cooling, crystallization, crushing, packaging is the finished product.
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.
Practical application of antioxidants
1, the research direction of antioxidant has turned to the development of high efficiency and multi energy additives and reactive antioxidants. The antioxidant BHT is widely used in industrial use, and the following is for its detailed use. It must be emphasized that oxidation inhibitor is not recommended.
1, antioxidant BHT, can inhibit or delay the oxidative degradation of plastic or rubber and prolong the service life.
2, antioxidant BHT can prevent the increase of acid value or viscosity of lubricating oil and fuel oil.
3, antioxidant BHT is synthetic rubber (SBR, Ding Jing, PU, Shun d), polyethylene, PVC stabilizer, antioxidant phenolic antioxidant BHT is commonly used in rubber antioxidant BHT, natural rubber, butadiene, styrene, isoprene, Ding Ji, Ding Jing, such as ethylene propylene synthetic rubber, acrylic latex and hot oxygen products aging has a protective effect, antioxidant BHT can inhibit the pollution of copper, and anti ozone and wax and various factors can prevent the climate of vulcanizate damage this product in the rubber is easy to disperse, antioxidant BHT can be directly mixed with rubber or latex added as a dispersion, can be used for manufacturing tire side wall, white the bright color and transparent color, all kinds of rubber and dairy products, daily necessities, health food, blankets, shoes and rubber, synthetic rubber antioxidant BHT can also be used as a postprocessing and storage Stabilizers.
4, the solubility of antioxidant BHT is: ethanol 25% (20), soybean oil 30% (25), cotton seed oil 20% (25), lard 40% (40).
5, antioxidant BHT as food additives in food can delay rancidity. Antioxidant BHT is used in animal and vegetable oils and foods containing plant oils and fats. In addition, antioxidant BHT can also be used in ink, adhesives, leather, casting, printing and dyeing, coating and electronics industry.
6, antioxidant BHT is also a stabilizer for cosmetics, medicine and so on. The amount of antioxidant BHT added: 0.01%-2%.
7. Antioxidant BHT is a good anti oxygen additive for all kinds of petroleum products. Antioxidant BHT has the best anti oxygen effect when its working temperature is 100 degrees. Antioxidant BHT is widely used in turbine oil, transformer oil, hydraulic oil, heat conduction oil, brake oil, spindle oil and precision mechanical oil and paraffin. The antioxidant BHT can be directly or transferred into the mother liquor to be added to the product. In order to improve the anti oxygen performance of the product and prolong the service life of the product. Antioxidant BHT is combined with long chain alkaline ZDDP, TCP metal reducing and rust inhibitor, and can be used to modulate antiwear hydraulic oil and other products. The dosage is generally 0.11%.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
The antioxidant structure determines its anti oxygen performance. The structure of the main antioxidant has a great relationship with its oxygen resistance.
It is known from the oxidation mechanism that the structure of a good antioxidant should have the following properties:
1, with a lively hydrogen atom, it should be more active than the active hydrogen atom on the polymer chain.
2, the free radicals of the antioxidant should have sufficient stability and can not lead to a new free radical reaction.
3, the antioxidants themselves should be more difficult to oxidize, otherwise they are oxidized.
Action mechanism of antioxidant
1. Stability of polymers using a broken chain antioxidant
The mechanism of reactive species reaction of antioxidants in intervention chain, namely, segment chain donor mechanism (CB-D) and segment chain receptor mechanism (CB-A).
The typical CB-D mechanism is the free radicals of peroxidation and the inhibitors such as phenols, followed by the reaction between aromatic amines. The free radical produced from the inhibitor AH can eliminate a peroxidase group PO2 as the reaction formula.
2. Stability of polymer using pre antioxidant
Preventive or auxiliary antioxidants can decompose hydroperoxide but do not form free radical intermediates. Therefore, they prevent the decomposition of hydrogen peroxide from free radicals to chain branching.
3. Synergism between antioxidants
A famous example is the application of cinnamoyl thiocarbamate (DLTDP) or double stearyl thiocarbamate (DSTDP) and sterically hindered phenol in some polymers' thermal stability. Another important example of synergy is the synergistic effect of sterically hindered phenol and phosphite on improving the stability of polyolefin melt.
Triphenyl phosphite (antioxidant, stabilizer TPPi) production process
1. Phosphorus oxychloride as the direct method (also called thermal method) phenol with pyridine and anhydrous benzene as solvent, in no more than 10 ℃ temperature, slowly add oxygen phosphorus chloride, then under reflux temperature, the reaction of 3 ~ 4 h. After cooling to room temperature, the reactants are washed by water to recycle pyridine. After centrifugal dehydration, the reagents are dehydrated with dried sodium sulfate, which is filtered to remove sodium sulfate. The first atmospheric distillation recovery of benzene, vacuum distillation, collected 243 ~ 245 ℃ (1.47 kPa) fraction, by cooling, crystallization, crushing is the finished product.
2. After phenol melting, stirring under add phosphorus trichloride under 25 ℃, Triphenyl phosphite is generated; Then heat up to 70 ℃ ventilation with chlorine gas, generated two chlorinated triphenyl phosphate; Again at 50 ℃ water hydrolysis, triphenyl phosphate. The hydrolysate with 5% soda solution for neutralization, water washing, the evaporation and vacuum distillation, collected 243 ~ 245 ℃ (1.47 kPa) fractions, cooling, crystallization, crushing, packaging is the finished product.
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.
Practical application of antioxidants
1, the research direction of antioxidant has turned to the development of high efficiency and multi energy additives and reactive antioxidants. The antioxidant BHT is widely used in industrial use, and the following is for its detailed use. It must be emphasized that oxidation inhibitor is not recommended.
1, antioxidant BHT, can inhibit or delay the oxidative degradation of plastic or rubber and prolong the service life.
2, antioxidant BHT can prevent the increase of acid value or viscosity of lubricating oil and fuel oil.
3, antioxidant BHT is synthetic rubber (SBR, Ding Jing, PU, Shun d), polyethylene, PVC stabilizer, antioxidant phenolic antioxidant BHT is commonly used in rubber antioxidant BHT, natural rubber, butadiene, styrene, isoprene, Ding Ji, Ding Jing, such as ethylene propylene synthetic rubber, acrylic latex and hot oxygen products aging has a protective effect, antioxidant BHT can inhibit the pollution of copper, and anti ozone and wax and various factors can prevent the climate of vulcanizate damage this product in the rubber is easy to disperse, antioxidant BHT can be directly mixed with rubber or latex added as a dispersion, can be used for manufacturing tire side wall, white the bright color and transparent color, all kinds of rubber and dairy products, daily necessities, health food, blankets, shoes and rubber, synthetic rubber antioxidant BHT can also be used as a postprocessing and storage Stabilizers.
4, the solubility of antioxidant BHT is: ethanol 25% (20), soybean oil 30% (25), cotton seed oil 20% (25), lard 40% (40).
5, antioxidant BHT as food additives in food can delay rancidity. Antioxidant BHT is used in animal and vegetable oils and foods containing plant oils and fats. In addition, antioxidant BHT can also be used in ink, adhesives, leather, casting, printing and dyeing, coating and electronics industry.
6, antioxidant BHT is also a stabilizer for cosmetics, medicine and so on. The amount of antioxidant BHT added: 0.01%-2%.
7. Antioxidant BHT is a good anti oxygen additive for all kinds of petroleum products. Antioxidant BHT has the best anti oxygen effect when its working temperature is 100 degrees. Antioxidant BHT is widely used in turbine oil, transformer oil, hydraulic oil, heat conduction oil, brake oil, spindle oil and precision mechanical oil and paraffin. The antioxidant BHT can be directly or transferred into the mother liquor to be added to the product. In order to improve the anti oxygen performance of the product and prolong the service life of the product. Antioxidant BHT is combined with long chain alkaline ZDDP, TCP metal reducing and rust inhibitor, and can be used to modulate antiwear hydraulic oil and other products. The dosage is generally 0.11%.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
Spanish
French
Italian
Portuguese
Japanese
Korean
Arabic
Russian