UV-curable acrylic coatings containing biomacromolecules: A new fire retardant strategy for ethylene-vinyl acetate copolymers

This work aims at demonstrating the suitability of selected biomacromolecules, namely caseins and deoxyribonucleic acids, as low environmental impact flame retardant additives for UV-curable coatings. To this aim, Bisphenol A hydroxyl ethyl diacrylate was utilized as UV-curable system, in the presence of a suitable photoinitiator (i.e. 2-hydroxy-2-methyl-1-phenylpropan-1-one), for coating ethylene-vinyl acetate copolymer thick plates. The flame retardant features of the coatings were evaluated in the presence of caseins or deoxyribonucleic acids – DNA – (at 10 and 15 wt.% loading) or a mixture of the two biomacromolecules (15 wt.% total loading) embedded in the UV-curable coating system, by means of forced combustion (i.e. cone calorimetry) tests. The coatings containing the biomacromolecules (namely 10 wt.% of DNA or 15 wt.% of casein) showed a decrease of peak of heat release rate and an increase of the time to peak as compared to the unfilled UV-cured counterparts. The proposed strategy may represent a possible starting point for the development of green and durable alternatives to the use of standard and more environmental impacting flame retarded coatings.