Compounding World’s annual review of flame retardants notes high interest and development of all types of PIN FR systems. New grades of phosphonates and other PIN chemistries, with specific PIN synergists, aim to achieve both UL 94 V-0 for thin wall sections and demanding Glow Wire Ignition requirements, e.g. in polyamides, including with glass fibres. An objective is to improve fire safety of unattended electronic equipment. New polycarbonate grades aim to replace use of perfluorinated sulphates in polycarbonate sheets and films and other polymers. Phosphorus-nitrogen PIN FRs are particularly effective in reducing smoke emissions, essential in e.g. railway applications, and can also prevent dripping. Developments in mineral PIN FRs achieve increasingly demanding fire safety specifications, e.g. for electric vehicles, whilst improving processing and mechanical properties. PIN synergists, such as performance clays, can be combined with mineral PIN FRs. Other PIN innovations proposed include graphene, silsesquioxanes, ionic liquids. New carrier polymers or PIN FRs or copolymers offer promising developments in fire and material performance, and specific additives are being developed to facilitate recycling of plastics, including with PIN FRs, by repairing polymer structure damaged by reprocessing.
“Flame retardant focus turns to green gains”, Compounding World (AMI CW) December 2022 www.compoundingworld.com and direct link to article.