Properties and performance of fire resistant eco-composites using polyhedral oligomeric silsesquioxane (POSS) fire retardants

Fire retardants are combined with polymer resins to reduce their flammability, decrease production of volatiles and inhibit pyrolysis. The goal of this work is to develop environmentally friendly fire retardant vinyl ester resin composites by blending fatty acid vinyl ester (FAVE) resins with environmentally friendly particulate fire retardants: polyhedral oligomeric silesquioxanes (POSS), while comparing them to similar composites with talc, a standard inorganic filler. Various concentrations of POSS or talc filler were blended into commercial and FAVE brominated vinyl ester resins, Derakane 510A-40 and FAVE-Br, respectively, and commercial and FAVE non-brominated vinyl ester resins, Derakane 441-400 and FAVE-L, respectively. Thermo-mechanical characterization of the new eco-composites was conducted using dynamic mechanical analysis and thermo-gravimetric analysis. Most POSS additives performed no better than talc in improving the composite performance relative to that of the neat resin. Yet, composites reinforced with methacryl POSS (MA0735) slightly outperformed the other POSS additives and talc. This POSS additive maintained resin viscosity, improved Tg, increased cross-link density, and increased flame retardance. However, the flame retardance of even this relatively high performing POSS-filled composite was very poor compared to that of brominated resins and the thermo-mechanical improvements relative to talc were small.