Polymers are subject to attack from various outside sources throughout their life cycle, during polymerization, processing and the end-use application. Degradation which primarily consists of a change in the molecular weight characteristics of a polymer, can manifest itself in a variety of forms. These include discoloration, change in viscosity, loss of physical properties, loss of clarity and surface crazing.
Antioxidants masterbatches are additive masterbatches which are incorporated at low concentrations to inhibit or retard polymer oxidation and its ensuing degradative effects.
Antioxidants, according to masterbatch producers, are required to protect polymers from oxidative degradation during processing and end use, are typically added by resin producers as part of their manufacturing process. Stabilization packages typically include a phenolic primary anti-oxidant which provides processing stability and long term heat stability to polymers such as polypropylene, polyethylene, polyamide, polyester, polystyrene, polyurethane and polyvinyl chloride. Phosphite-based secondary antioxidants provide excellent processing stability. Phosphites are also synergistic with hindered phenol primary antioxidants. Phenolic antioxidants and phenolic phosphite blends offer excellent protection against thermo-oxidative degradation and discoloration of polymers.
Antioxidant masterbatches are produced by leading masterbatch manufacturers in India like REPIN Masterbatches. They are also used in various stages of the processing of different polymers to give the required properties like OIT, in cable industries, smell & colour problems to be reduce in reprocessing industry properties retaining the flow and mechanical properties in virgin, heat sensitive polymers etc. The growth of antioxidant in the world is around 10%. Antioxidant Masterbatches are used in various polymers processing industries like:
- Cable industries
- Filled compounds
- Blow Moulding
- BOPP films
The masterbatches’ recommended dosage is at around 1 – 3 % levels. The choice of antioxidant depends on factors such as compatibility, colour and thermal stability, volatility and stabilizer efficiency.