Flame spread behaviour of Polydimethylsiloxane (PDMS) membranes in 1 g and µg environments

Diffusion flame behaviour and silica ash (SiO2) production were experimentally studied for various Polydimethylsiloxane (PDMS) membrane thicknesses (0.125 mm to 1.0 mm) in normal gravity during microgravity flight experiments. The flames established on vertical samples (300 length) subjected either opposed or concurrent forced flows (both laminar turbulent), assimilating the NASA Test 1 that is use spacecraft material selection. spread rate was observed be steady could estimated using classical theory. Under flow, only very high flows. flame-spread ranged from 0.5 1.5 mm/s, while case between 0.1 12 mm/s. transport of found affect heat balance a manner resulted unsteady spread. For spread, other hand, showed irrelevant. extinction heavily dominated by silica-ash, flames, due kinetics (at flows). In environments, deposition anticipated dominate near-limit as well. These results suggest silica-based products might less flammable than similar materials such common thermoplastics (PP PE) used wire jackets.