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Green process for fireproofing plastics

DOPO derivativesFire protectionflame retardantOrganophosphorusplasticPlastic fireproofingPlastica ignifugaSustainable chemistry


Organic Phosphorus Flame Retardants, on use for their fire-resistant properties, can now be produced with a more efficient and ecological synthetic strategy, in particular P(=O)-heteroatom derivatives of dibenzooxaphosphacycles – which are compounds arousing great interest because of their multiple structural diversifications and good flame retardant effect in both gas and condensed phase.

Technical features

The European Commission put additional restrictions to the use of halogen-based flame retardants starting from 2002, due to their harmful effects on health and the environment. Organophosphorus Flame Retardants are therefore rising as one of the most promising alternatives for plastic fireproofing in a wide range of applications, particularly aromatic derivatives containing the P(=O)-heteroatom moiety, such as DOPO-derivatives. Nevertheless, synthetic pathways for these compounds requires the use of highly impactful agents towards the environment (e.g. carbon tetrachloride [CCl4], a carcinogen compound and with ozone-depleting and greenhouse gas effect). Inventors have identified an efficient, industrially scalable and more sustainable process (TRL4) for functionalization of molecules such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO).

Possible Applications

  • Flame retarded thermoplastic materials (e.g. ABS, PS, SAN, TPU, PMMA);
  • Flame retarded polymeric resins and coatings (e.g. PUR, NIPU, Epoxy, Acrylic).


  • More economically efficient and industrially scalable strategy;
  • More sustainable process.