Metal Deactivators and Acid Scavengers

Inserts should, therefore, be made of light metal or be nickel or chromiiun plated. No adverse effect with brass screw fittings has been detected at temperatures below 100 °C. 

Metal deactivators and acid scavengers retard metal-catalysed reactions. They are chelating agents that effectively retard metal-catalysed oxidation. Metal deactivators are nsed to deactivate metal residues present in formulations due to catalyst residues, impurities in additives, direct contact with copper in wire and cable applications, and metal inserts. 

Metals (copper and copper alloys, nickel, iron) have a strong adverse effect on PE because they accelerate degradation. Metal deactivators (organic molecnles containing heteroatoms or functional groups such as hydroxyl or carboxyl) act by chelation of the metal to form inactive or stable complexes. The concentration used is about 1 %. Acid scavengers (or antiacids) are used to neutralise acidic catalyst residues. Calcium or zinc stearate are commonly used, and also function as internal lubricants. Inserts should be made of light metal or he nickel or chromium plated. 

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