Bioinspired-Polyamidoamine/Nanoparticle coatings as high-performing flame retardants for cellulosic fabrics
PANACEA project dealt with the design of bioinspired-polyamidoamine/nanoparticle coatings as high-performing flame retardants (FRs) for cellulosic fabrics. The main purpose is to synthesize environment-friendly, non-toxic FRs with performances comparable to those of the best traditional FRs currently used for cellulosic textiles. The overall objective is to study novel coatings based on polyamidoamines (PAAs), a family of synthetic water-soluble biocompatible and biodegradable polymers, bearing in their repeating units the same organic functions present in proteins, that were proven efficient FRs for cotton by the PANACEA supervisor. PAA preparation can be considered green and scalable as obtained by stepwise polyaddition of prim- or sec-amines to bisacrylamides in water, at room temperature and with no added catalysts. Furthermore, the synergism between PAAs and some nanoparticles (NPs) will be studied and exploited for i) improving the FR properties of selected PAAs and ii) reducing the final add-on of the most performing PAAs. PAAs with carboxylic or guanidine groups will be combined with layered double hydroxides and zinc borate nanorods in order to suppress cotton combustion in the most drastic fire scenarios, guaranteeing a low emission of combustion products. In parallel, sulphur-based-PAAs will be combined with graphene and graphene oxide with different sizes and oxidation grades. These coatings will be obtained by a water-based finishing treatment of impregnation/exhaustion and/or Layer-by-Layer assembly of biocompatible PAAs and NPs. Both these approaches are easily scalable, hence adaptable to the needs of pre-industrial production, conclusive objective of PANACEA. To this aim, the durability of such treatments will be objective of the project and achieved by initially grafting of FR PAA bearing reactive vinyl terminals through radical reactions in the presence of thermal or redox initiators, and then interacting with specific synergist NPs.