The connections and differences between antioxidants and heat stabilizers in PVC production
Thread Content
As the title suggests, 1. Antioxidants/heat stabilizers used in the production of PVC resin? 2. Antioxidants/heat stabilizers for post-processing? What are the conceptual similarities and differences between the two? What are the similarities and differences among chemical species? Requirements for the usage scenario?
Current water-soluble terminators generally contain antioxidants, while heat stabilizers are not widely used in high-grade resins at present. The stabilizers used by PVC manufacturers include calcium-zinc compounds, barium stearate, and epoxy soybean oil. Antioxidants used include amine-based antioxidants, 4,4-methylenedioxy (2,6-di-tert-butylphenol), phosphites, etc.
1. Antioxidants/heat stabilizers for PVC resin production: These are used to counteract the effects of oxygen molecules that enter the reaction mixture, preventing oxygen atoms from attaching to the PVC chains and creating weak structures that could affect the thermal stability of the resin. 2. Antioxidants/heat stabilizers for post-processing: These are used to capture oxygen molecules that enter the powder mixture, allowing oxygen to react preferentially with the antioxidants and thereby preventing oxidation of the PVC chains, which could otherwise lead to chain breaks and affect the thermal stability of the product.