Polycyclic silicone membranes. Synthesis, characterization and permeability evaluation

In this work, membranes based on polycyclic silicone networks were synthesi zed from different cyclic siloxanes, through hydrosilylation reactions. The se membranes showed good thermal stability, glass transition higher than co nventional silicone networks and the absence of pores and phase segregation , with roughness surface. The nanomorphology of the materials was studied b y small angle X-ray scattering. Some samples produced practically no scatte ring and some produced patterns that are typical of non-particulate systems . The gas permeability behavior of the membranes was investigated, showing permeability coefficients higher than those observed for some organic polym ers, and selectivity coefficients higher than those found for PDMS based me mbranes. (C) 2000 Elsevier Science Ltd. All rights reserved.