The use of POSS as synergist in intumescent recycled poly(ethylene terephthalate)

Fire retarded poly(ethylene terephthalate) (PET) has been obtained by the incorporation of octamethyl polyhedral oligomeric silsesquioxane (OMPOSS) and Exolit OP950, a phosphinate-based compound, in recycled PET. The presence of Exolit OP950 only leads to intumescence explaining the improvement of the flame retardancy. The addition of OMPOSS leads to a synergistic effect considerably increasing the fire retarding performances of the polymer in terms of cone calorimetry and limiting oxygen index even if a small thermal stabilisation as well as a very poor dispersion of OMPOSS and OP950 into the matrix has been observed.