News Details
Polyethylene antioxidants
2017-12-28 15:37:49
Polyethylene antioxidants
The effects of polyethylene antioxidant and light stabilizer on the aging properties of high density polyethylene were studied. The results showed that UV326 was better than UV531 when uv absorber was used alone. The 770 and UV326 completions are better when the uv absorber and the hindered amine 770 are matched.
The anti-aging performance of polyethylene is obviously improved after polyethylene antioxygenation and photostabilizer, especially the effect of antioxidant 1010 and anti-oxygen agent 168. The study also showed that the appropriate dosage of anti-oxygen agent 1010 and anti-oxidant 168 was 0.1 and 0.15 respectively when used with photostabilizer.
Plastic in the processing and use process, due to light, heat, oxygen and other combination of internal and external factors, and cause the degradation or crosslinking, make its performance becomes bad, yellow appearance, so that the loss of use value.
Polyethylene material for ultraviolet (uv) absorption capacity is very low, not easy to produce photochemical reaction in theory, but in fact it is in the process of polymerization, processing, can form a small amount of hydrogen peroxide on the structure and some impurities, containing carbonyl and prone to aging, so the aging performance of polyethylene material is still relatively large, to improve the aging resistance performance is very important.
The photooxidation of polyethylene resin in sunlight is a radical chain reaction. To slow down the photooxygen aging effect of the resin, it is necessary to add the light stabilizer to block the continuous operation of the chain reaction.
According to the mechanism of action, the light stabilizer can be divided into four categories: optical screening agent, ultraviolet absorber, quenching agent and retarded amine photostabilizer, which can be used in different stages of polyethylene aging. In order to improve the aging resistance of polyethylene, two or more kinds of light stabilizers are commonly used. Zhang liji studied the combination of ultraviolet absorbent and obstructed amine photostabilizer, and found that UV531 and blocked amine GW540 had some synergistic effects.
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.
Hindered amine 770 is an efficient and low - toxic light stabilizer and has good compatibility and dispersion with resin. However, the effects of uv absorbents on the aging resistance of 770-compound polyethylene were not reported. The photoaging of polymers is the result of a series of complex reactions to uv radiation.
Polymer molecular chain under uv irradiation most dissociation, not just in the excited state, are easily with oxygen molecule chain reaction, formation of free radicals, photodegradation process of chain reaction. Therefore, the use of antioxidants for inhibiting material light oxygen aging plays an important role, through the synergy of light stabilizers and antioxidants, can better play to the role of the light stabilizer, make the light aging resistant polymer improved better.
However, there are few studies on the effects of photostabilizers and antioxidants on the effects of polyethylene photoageing. Choose UV531 UV3262 kinds of uv absorbent and hindered amine light stabilizer 770, studied the different light stabilizer distribution system on the properties of polyethylene aging effects, and through the light stabilizer, with antioxidants to light stabilizers and antioxidants were studied after matching the influence of the aging resistance of polyethylene material.
Raw materials and auxiliaries. High density polyethylene (HDPE):LA-50D012(5000S) type; PE wax; Calcium stearate; Antioxidants 1010 and 168, uv absorbent UV531 and UV326, blocked amine 770.
Preparation of samples. Will 100 HDPE resin, 0.5 to 1 PE wax, stearic acid calcium and the ratio of different complex of light stabilizers and antioxidants (table 1) in table 3), respectively in 50 e high-speed mixer high-speed mixing 0.5 h, then in injection molding machine, injection into a spline on standardized tests. The dosage range of general uv absorber was 0.08 0.12, and the experiment was 0.1.
Aging test. The effects of heat, oxygen, uv and humidity on the properties of polyethylene were simulated by using QUV. The aging time is 100h, 300h, 500h, 700h and 1000h respectively. The test conditions are air atmosphere, and each cycle includes 10min spray, 8h uv aging (temperature is 50e), then 4h condensation (45e). The wavelength of uv light is 340nm and the radiation intensity is 1.19 W/m2.
Performance testing. Tensile properties: according to GB1040) 92 standards, sample size @ 10 mm to 50 mm @ the dumbbell specimen of 4 mm, the ANS microcomputer control electronic universal material testing machine, tensile speed of 20 mm/min, the test temperature to room temperature, each group of three samples, the tensile strength, elongation at break test results, take the arithmetic mean. The test results show that the fracture strength retention rate and elongation of fracture elongation at the time of aging are compared.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
The effects of polyethylene antioxidant and light stabilizer on the aging properties of high density polyethylene were studied. The results showed that UV326 was better than UV531 when uv absorber was used alone. The 770 and UV326 completions are better when the uv absorber and the hindered amine 770 are matched.
The anti-aging performance of polyethylene is obviously improved after polyethylene antioxygenation and photostabilizer, especially the effect of antioxidant 1010 and anti-oxygen agent 168. The study also showed that the appropriate dosage of anti-oxygen agent 1010 and anti-oxidant 168 was 0.1 and 0.15 respectively when used with photostabilizer.
Plastic in the processing and use process, due to light, heat, oxygen and other combination of internal and external factors, and cause the degradation or crosslinking, make its performance becomes bad, yellow appearance, so that the loss of use value.
Polyethylene material for ultraviolet (uv) absorption capacity is very low, not easy to produce photochemical reaction in theory, but in fact it is in the process of polymerization, processing, can form a small amount of hydrogen peroxide on the structure and some impurities, containing carbonyl and prone to aging, so the aging performance of polyethylene material is still relatively large, to improve the aging resistance performance is very important.
The photooxidation of polyethylene resin in sunlight is a radical chain reaction. To slow down the photooxygen aging effect of the resin, it is necessary to add the light stabilizer to block the continuous operation of the chain reaction.
According to the mechanism of action, the light stabilizer can be divided into four categories: optical screening agent, ultraviolet absorber, quenching agent and retarded amine photostabilizer, which can be used in different stages of polyethylene aging. In order to improve the aging resistance of polyethylene, two or more kinds of light stabilizers are commonly used. Zhang liji studied the combination of ultraviolet absorbent and obstructed amine photostabilizer, and found that UV531 and blocked amine GW540 had some synergistic effects.
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.
Hindered amine 770 is an efficient and low - toxic light stabilizer and has good compatibility and dispersion with resin. However, the effects of uv absorbents on the aging resistance of 770-compound polyethylene were not reported. The photoaging of polymers is the result of a series of complex reactions to uv radiation.
Polymer molecular chain under uv irradiation most dissociation, not just in the excited state, are easily with oxygen molecule chain reaction, formation of free radicals, photodegradation process of chain reaction. Therefore, the use of antioxidants for inhibiting material light oxygen aging plays an important role, through the synergy of light stabilizers and antioxidants, can better play to the role of the light stabilizer, make the light aging resistant polymer improved better.
However, there are few studies on the effects of photostabilizers and antioxidants on the effects of polyethylene photoageing. Choose UV531 UV3262 kinds of uv absorbent and hindered amine light stabilizer 770, studied the different light stabilizer distribution system on the properties of polyethylene aging effects, and through the light stabilizer, with antioxidants to light stabilizers and antioxidants were studied after matching the influence of the aging resistance of polyethylene material.
Raw materials and auxiliaries. High density polyethylene (HDPE):LA-50D012(5000S) type; PE wax; Calcium stearate; Antioxidants 1010 and 168, uv absorbent UV531 and UV326, blocked amine 770.
Preparation of samples. Will 100 HDPE resin, 0.5 to 1 PE wax, stearic acid calcium and the ratio of different complex of light stabilizers and antioxidants (table 1) in table 3), respectively in 50 e high-speed mixer high-speed mixing 0.5 h, then in injection molding machine, injection into a spline on standardized tests. The dosage range of general uv absorber was 0.08 0.12, and the experiment was 0.1.
Aging test. The effects of heat, oxygen, uv and humidity on the properties of polyethylene were simulated by using QUV. The aging time is 100h, 300h, 500h, 700h and 1000h respectively. The test conditions are air atmosphere, and each cycle includes 10min spray, 8h uv aging (temperature is 50e), then 4h condensation (45e). The wavelength of uv light is 340nm and the radiation intensity is 1.19 W/m2.
Performance testing. Tensile properties: according to GB1040) 92 standards, sample size @ 10 mm to 50 mm @ the dumbbell specimen of 4 mm, the ANS microcomputer control electronic universal material testing machine, tensile speed of 20 mm/min, the test temperature to room temperature, each group of three samples, the tensile strength, elongation at break test results, take the arithmetic mean. The test results show that the fracture strength retention rate and elongation of fracture elongation at the time of aging are compared.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
http://www.yaruichem.com
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