Effect of Crosslinking Agent Length on the Transport Properties of Polydecylmethylsiloxane-Based Membranes

The effect of crosslinking agent length on transport properties of membranes based on polydecylmethylsiloxane (PDecMS) has been studied. Dense PDecMS membranes reinforced with a stainless-steel grid and crosslinked with either 1,7-octadiene or vinyl-terminated polydimethylsiloxane (Mn = 500 g/mol) have been synthesized. The permeability of light hydrocarbons (methane, propane, n-butane) and separation characteristics of the membranes have been studied using an eight-component model mixture simulating the composition of the associated gas of an oil field. It was first found that crosslinking agent length has a significant effect on the selectivity of PDecMS-based membranes. Short crosslinking with 1,7-octadiene provides high gas permeability selectivities both in the case of permeability of individual gases and in the separation of a gas mixture.