Characterization and CO₂ sorption properties of poly[methacryloxypropylheptacyclopentyl‐T8‐silsesquioxane‐ co‐3‐methacryloxypropyltris(trimethylsiloxy)silane]

Abstract

Poly[methacryloxypropylheptacyclopentyl-T8-silsesquioxane (MAPOSS)-co-3-methacryloxypropyltris(trimethylsiloxy)silane (SiMA)] was synthesized through free radical polymerization. The physical and carbon dioxide (CO 2 ) sorption properties of the copolymer membranes were investigated in terms of the MAPOSS content. As the MAPOSS content increases, the membrane density increased, suggesting a decrease in the fractional free volume. In addition, the thermal stability was improved with increasing the MAPOSS content. These are because of the polyhedraloligomericilsesquioxane (POSS) units that restrict the high mobility of poly-(SiMA) segments. The glass transition temperature, T g of the copolymers was single T g based on the differential scanning calorimetry, suggesting that the copolymers were random and not phase separation. Based on the CO 2 sorption measurement, the POSS units play a role in reducing Henry's dissolution by suppressing the mobility of the poly(SiMA) component, while POSS units increase the nonequilibrium excess free volume, which contributes to the Langmuir dissolution. Based on these results, the introduction of MAPOSS unit is one of the effective ways to improved the thermal stability and CO 2 sorption property due to the enhancement of the polymer rigidity.

Sorption Behavior of Compressed CO2 and CH4 on Ultrathin Hybrid Poly(POSS-imide) Layers

“…The pronounced swelling is due to more flexible poly­(POSS-imide) network as compared to that of the 5 wt % sample. The flexibility is highest for the layers prepared with the lowest POSS concentrations, which is in line with observations from others . Indeed, for the 0.9 wt % sample up to 20 bar CO 2 pressure the reactive index show a similar trend as compared to the 2.5 wt % sample.…”

Thermal and gas permeation properties of copolymers derived from 3‐methacryloxypropyltris(trimethylsiloxy)silane and adamantyl group‐containing methacrylate derivatives

“…Conversely, two broad peaks were observed at 2θ = 12° ( d ‐spacing = 7.4 Å) and 2θ = 17.4° ( d ‐spacing = 5.1 Å) in poly(SiMA). These two broad halos indicate the distance between polymer segments in a small angle, whereas that in the large angle was attributed to the intermolecular distance between long side chains . Interestingly, all of the copolymers with 50 mol % adamantane showed an extended broad halo at 2θ = 10–20°, and this halo perfectly separated the two peaks at 10 mol % adamantane in common with poly(SiMA).…”

“…These two broad halos indicate the distance between polymer segments in a small angle, whereas that in the large angle was attributed to the intermolecular distance between long side chains. 37 Interestingly, all of the copolymers with 50 mol % adamantane showed an extended broad halo at 2h 5 10-208, and this halo perfectly separated the two peaks at 10 mol % adamantane in common with poly(SiMA). Therefore, all of the copolymers with 10-50 mol % adamantine have d-spacing of adamantane polymer and poly(SiMA).…”

“…Furthermore, adamantane and siloxane exhibited good compatibility, because introducing adamantane and siloxane with identical structures as substituents is expected to increase thermal resistance and decrease dielectric constant and photo transparency . In our previous study, we synthesized a novel random copolymer, which comprised polyhedraloligomericilsesquioxane (POSS) with cage‐type structure that is similar to that of adamantane and SiMA . However, POSS structure is approximately 2.5 times larger than adamantane (structure diameter: POSS, 1.5 nm; adamantane, 6.5–7.1 Å).…”

“…[34][35][36] In our previous study, we synthesized a novel random copolymer, which comprised polyhedraloligomericilsesquioxane (POSS) with cage-type structure that is similar to that of adamantane and SiMA. 37 However, POSS structure is approximately 2.5 times larger than adamantane (structure diameter: POSS, 1.5 nm 38 ; adamantane, 6.5-7.1 Å 39 ). It is considered that the more bulky pendant group in the polymer, the membrane is the more hard and brittle because of restrict mobility of polymer chain.…”