Thermal degradation of polysiloxanes with hetero-units in the chain and modified with low molecular weight additives

Synthesis and thermal properties of modified room temperature vulcanized (RTV) silicone rubber using polyhedral oligomeric silsesquioxane (POSS) as a cross linking agent

“…45,46,48 Similarly, cyclic dimethylsiloxanes generate and keep increasing slightly during the rst degradation stage of TOPO-PDMS, showing the identical behaviour of PDMS with incompletely reacted hydroxyl terminal which can participate in a 'back biting' reaction in accordance with the end-initiated unzipping mechanism. 42,45,49 At the second degradation stage of TOPO-PDMS from 468 C to 683 C, the concentration of dimethylsiloxanes increases distinctly and methane generates owing to the random degradation mechanism of PDMS main chain, which is caused by increasing chain mobility and molecular motion as the temperature elevated. In this mechanism, a exible chain would be more easily degraded than a rigid chain, since the probability of chain motion should be dependent of chain exibility.…”