Crosslinking of Polydimethyl Siloxane Copolymers with Aromatic Dianhydrides: The Study of Thermal and Flame Retardant Properties

Aromatic dianhydrides have been identified as potential candidates for crosslinking with biocatalytically synthesized siloxane copolymers containing a functional amino group on the isophthalate moieties. We present the synthesis, characterization, thermal and flame retardant properties of this novel class of crosslinked organo-siloxane copolymers. We also discuss the effect of the concentration of one of the crosslinkers, 1,2,4,5-benzenetetracarboxylic dianhydride (DAH), on thermal decomposition and flame retardant properties using thermogravimetric analysis (TGA) and pyrolysis combustion flow calorimetry (PCFC) studies. The char yields were improved in all the polymers crosslinked with the various aromatic dianhydrides. The heat release capacity of a polymer crosslinked with 20% DAH, compared to the pure polymer, was tremendously reduced from 190 J/gK to 100 J/gK. The decomposition kinetics from TGA showed that the crosslinked polymer is thermally more stable than the non-crosslinked polymer.