Résumé
Using thermogravimetric analysis (TGA) this research investigates how polymer composition, temperature, and oxygen concentration influence degradation mechanisms of fluorosilicones at high temperatures. The findings reveal that even low oxygen levels significantly impact the degradation of model unfilled fluorosilicone homopolymer (HP), with further formulation changes reducing this effect. Overall, the copolymerization with dimethylsiloxane and vinylmethylsiloxane lower degradation kinetics. The stability is increased for model rubbers in which silica particles are incorporated, indicating that silica provides an antioxidative effect, and in cured samples obtained by peroxide crosslinking using dicumyl peroxide (DCP) combined with CaCO₃ or pure 2,5dimethyl-2,5-di-(tert-butylperoxy)hexane (DBPH). Analysis of macromolecular changes using modulated differential scanning calorimetry (MDSC) on HP reveals distinct degradation behaviors under oxygen at 250 • C and 280 • C possibly due to the appearance of a heterogeneous mechanism. These findings offer valuable insights into the thermo-oxidative stability of fluorosilicones.