Combination effect of polyhedral oligomeric silsesquioxane (POSS) and a phosphorus modified PMMA, flammability and thermal stability properties

The influence of two different types of polyhedral oligomeric silsesquioxane (POSS): trisilanolphenyl-POSS (Tr.POSS) and methacrylateethyl-POSS (MA.POSS) on thermal degradation and flammability properties of both PMMA and a phosphonated modified PMMA (copo.(MMA–MAPC1) has been investigated using TGA, PCFC and Py-GC/MS. The physical incorporation of MA.POSS in phosphonated modified PMMA (copo.(MMA–MAPC1)) enables to increase thermal stability properties compared to pristine phosphonated polymer due to the interaction between POSS radical sites and phosphorus species formed during thermal degradation. The reactive incorporation of POSS into PMMA was assessed by synthesizing copolymer and terpolymer of MA.POSS with MMA and MAPC1. It has been highlighted that, compared to the physical blends, the introduction of the POSS cage in the polymer chains induces a shift of degradation onset toward high temperature, an increase of the residue amount as well as a decrease of the heat release.