Silsesquioxane (SQ) membranes derived from 3-methacryloxypropyltrimethoxysilane and bis(trimethoxysilyl)ethane were successfully fabricated at low temperature via photo-induced sol-gel processing. Radical and cationic polymerization of SQ membranes showed high degrees of separation factor and permeance for water/isopropanol separation in pervaporation.

Stretched thin films composed of a thermoplastic elastomer, a polystyrene-block-poly(ethylene butylene)-block-polystyrene triblock copolymer (SEBS), and polyolefins, poly(ethylene-co-ethylacrylate) and poly(ethylene-co-propylene), were obtained by blow-molding, uniaxial stretching, and cooling to room temperature and the gas permeability of the stretched films was investigated. When the as-blown annealed film was subjected to uniaxial stretching in the machine direction, P O2 and P N2 increased with an increase in the stretching ratio K and approached a constant value at high stretching ratios. In addition, P O2 /P N2 decreased gradually with K and approached a value of 2.95-3.0. The reason for this unique gas permeation behavior is that the molecular mobility of poly(ethylene butylene) chains in a direction normal to the film increases and reaches an equilibrium state at around K 5 4.5. The change in gas permeability of the stretched films can be explained using a deformation model for the SEBS matrix.

No abstract

No abstract

Thin dense films composed of a thermoplastic elastomer [polystyrene‐block‐poly(ethylene butylene)‐block‐polystyrene triblock copolymer (SEBS)] and two polyolefins, poly(ethylene‐co‐ethylacrylate) and poly(ethylene‐co‐propylene), were obtained by blow molding, uniaxial hot stretching, and cooling to room temperature. In the resulting films, the dispersed polyolefin phase formed a 3D‐network structure which constrained the elastic recovery of the SEBS matrix phase. The presence of this network structure was a key factor in forming the thin dense films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013