Summary of research into integration of PIN (phosphorus, inorganic, nitrogen) fire resistance into polymers. This paper reviews studies reacting PIN compounds into different polymers including polyurethanes, polyamides, polyimides, polyesters, PET (polyethylene terephthalate), PLA (polylactic acid) and epoxies, as well as specific polymers such as polyoaxadiazoles, polybenzoxazines or polysiloxanes. Phosphorus compounds are indicated to be the most widely investigated for reaction into polymer matrices to impact flame retardancy, but also nitrogen, sulphur and silicon compounds, often with cross-linking. Combinations of phosphorus with other PIN compounds and modification of the polymer structure allow optimal fire resistance, with both solid and gas phase effects, whilst minimising loss of mechanical performance. Polymeric PIN systems produced with renewable and bio-based materials are also discussed.
“A survey of recent publications on polymers employing reactive, halogen-free flame-retardant functionalities”, B. Stovall & T. Long, Polymer International 2024 http://dx.doi.org/10.1002/pi.6673