Wuhan modern antioxidant
DATE：2020/12/18 9:06:02 / READ： / SOURCE：This station
Wuhan modern antioxidant
In the process of molding, storage and use of plastics, due to various factors, its structure changes, performance deteriorates, and gradually loses its use value.
Aging is manifested in (1) changes in the appearance of plastics (such as darkening, yellowing, etc.); (2) changes in physical and chemical properties (such as solubility, melt index, etc.); (3) changes in mechanical properties (embrittlement, hardening, elasticity decline); (4) deterioration of electrical properties. The external factors are light, oxygen, heat, electric field, radiation, stress and other physical factors, chemical factors such as solvent or chemical medium erosion, mold, insect bite and biological factors; the internal factors are the molecular structure and the role of additives. Among them, light, oxygen and heat are the most important factors, and the important way to restrain or delay the effect is to add light, oxygen and heat stabilizers. www.handern.com Air permeable membrane extrusion equipment
Definition and requirements
In the process of molding, storage and use of plastics, it is inevitable to contact with oxygen. Under certain conditions, oxidation reaction will occur and the plastic will be aged. In order to prevent or delay the oxidation, antioxidant should be added.
Antioxidants should meet the following requirements: (1) good oxidation resistance, (2) good compatibility with plastics, stable at processing temperature; (3) no influence on other properties of plastics, synergistic effect with other additives, at least no adverse reactions; (4) non toxic or low toxicity, no discoloration, little pollution.
Selection and evaluation of antioxidants
The general principle for the selection of antioxidants depends on their properties, including the following points:
(1) colorless or light colored non polluting phenolic antioxidants should be selected for discoloration and pollution light colored plastic products;
(2) The volatility with high molecular weight is less volatile. Low volatile compounds should be selected. Volatility is related to molecular structure, operation and use temperature, exposed surface size, air flow condition, etc; www.handern.com Air permeable membrane extrusion equipment
(3) Solubility requires high solubility in resin and low solubility in other media. Especially important is the solubility in water or solvent, which affects the extractability;
(4) The efficiency of the anti ozone agent depends on the migration to the surface,
(5) the stability requires stability to oxygen, light, heat and water;
(6) The best physical form is liquid and easily emulsified antioxidant;
(7) Synergistic effect the combination of amine and phenol chain reaction inhibitor and peroxide decomposition agent has synergistic effect. The evaluation of antioxidant performance generally starts from the following points: ① processing stability: ② thermal stability; ③ weather resistance; ④ extraction resistance; ⑤ volatility; ⑥ migration and frost spraying.
Copper resistant agent
Anti copper agent, also known as metal ion passivator, metal chelator or copper inhibitor, can prevent heavy metal ions (mainly copper) from causing oxidation of plastics. It is mainly used for cable material. www.handern.com Air permeable membrane extrusion equipment
The copper resistant agent should meet the following requirements: 1) strong ability to inhibit metal ions catalytic oxidation; 2) good compatibility with resin and easy dispersion; 3) no decomposition at processing temperature and low volatility; 4) non toxicity or low toxicity; 5) no effect on the properties of plastics; 6) low price.
In the process of molding, storage and use of plastics, due to various factors, its structure changes, performance deteriorates, and gradually loses its use value.
Aging is manifested in (1) changes in the appearance of plastics (such as darkening, yellowing, etc.); (2) changes in physical and chemical properties (such as solubility, melt index, etc.); (3) changes in mechanical properties (embrittlement, hardening, elasticity decline); (4) deterioration of electrical properties. The external factors are light, oxygen, heat, electric field, radiation, stress and other physical factors, chemical factors such as solvent or chemical medium erosion, mold, insect bite and biological factors; the internal factors are the molecular structure and the role of additives. Among them, light, oxygen and heat are the most important factors, and the important way to restrain or delay the effect is to add light, oxygen and heat stabilizers. www.handern.com Air permeable membrane extrusion equipment
Definition and requirements
In the process of molding, storage and use of plastics, it is inevitable to contact with oxygen. Under certain conditions, oxidation reaction will occur and the plastic will be aged. In order to prevent or delay the oxidation, antioxidant should be added.
Antioxidants should meet the following requirements: (1) good oxidation resistance, (2) good compatibility with plastics, stable at processing temperature; (3) no influence on other properties of plastics, synergistic effect with other additives, at least no adverse reactions; (4) non toxic or low toxicity, no discoloration, little pollution.
Selection and evaluation of antioxidants
The general principle for the selection of antioxidants depends on their properties, including the following points:
(1) colorless or light colored non polluting phenolic antioxidants should be selected for discoloration and pollution light colored plastic products;
(2) The volatility with high molecular weight is less volatile. Low volatile compounds should be selected. Volatility is related to molecular structure, operation and use temperature, exposed surface size, air flow condition, etc; www.handern.com Air permeable membrane extrusion equipment
(3) Solubility requires high solubility in resin and low solubility in other media. Especially important is the solubility in water or solvent, which affects the extractability;
(4) The efficiency of the anti ozone agent depends on the migration to the surface,
(5) the stability requires stability to oxygen, light, heat and water;
(6) The best physical form is liquid and easily emulsified antioxidant;
(7) Synergistic effect the combination of amine and phenol chain reaction inhibitor and peroxide decomposition agent has synergistic effect. The evaluation of antioxidant performance generally starts from the following points: ① processing stability: ② thermal stability; ③ weather resistance; ④ extraction resistance; ⑤ volatility; ⑥ migration and frost spraying.
Copper resistant agent
Anti copper agent, also known as metal ion passivator, metal chelator or copper inhibitor, can prevent heavy metal ions (mainly copper) from causing oxidation of plastics. It is mainly used for cable material. www.handern.com Air permeable membrane extrusion equipment
The copper resistant agent should meet the following requirements: 1) strong ability to inhibit metal ions catalytic oxidation; 2) good compatibility with resin and easy dispersion; 3) no decomposition at processing temperature and low volatility; 4) non toxicity or low toxicity; 5) no effect on the properties of plastics; 6) low price.
Author：admin