Synthesis and permeability properties of crosslinkable elastomeric poly(vinyl allyl dimethylsilane)s

Abstract

This article presents the results of a systematic synthesis study of elastomeric crosslinkable polysilicon olefins, the related thermal crosslinking kinetics, and the main permeability parameters recorded for inorganic gases (He, N 2 , O 2 , and CO 2 ) and C 1 -C 7 hydrocarbons. Poly(vinyl allyl dimethylsilane) (PVADMS; glass-transition temperature Ͻ 273°K) was obtained by the anionic polymerization of bifunctional vinyl allyl dimethylsilane monomer. The polymers were amorphous, high molecular compounds with mixed carbo-heterochain structures containing double bonds capable of intermolecular crosslinking under a thermal treatment. Thus, thermally crosslinked polymers exhibited a high resistance toward exposure to organic vapors, unlike noncrosslinked PVADMS. IR spectroscopy was used to investigate the polymer structural changes induced by the thermal treatment. An original technique based on a differential method was used to measure gas permeability during thermal crosslinking. PVADMS possessed higher permeability for C 1 -C 7 hydrocarbons than for inorganic gases (excluding CO 2 ), even after crosslinking. Permeability coefficients ranging from 140 to 1780 Barrer for He and CH 4 were found before crosslinking; the thermal crosslinking induced a nonlinear permeability decrease that could be correlated with the disappearance of the double bonds in the polymer structures, that is, cis-CHACHO, trans-CHACHO, and CH 2 ACHO in the side-chain position. According to the found properties, PVADMS could be used as a prospective material for the preparation of highly permeable selective membranes suitable for lower hydrocarbon and volatile organic compound recovery from various chemical and petrochemical process streams.

Synthesis, characterization, and hoping transport properties of HCl doped conducting biopolymer‐co‐polyaniline zwitterion hybrids

“…It was found that electrical conductivity was higher at pH 1 and very low at pH 12, indicating the inter conversion of emeraldine salt to emeraldine base of the attached PANI chains inside the zwitterion. 20 Thus pH dependent electrical conductivity is directly associated with the electronic transitions (as UV-vis evidences) within the hybrid material. It occurred probably due to protonation as well as deprotonation of PANI chains (generate -NH þ 3 at lower pH and -NH 2 at higher pH).…”

“…They have controlled electrical conductivity, good adhesion properties, high mechanical strength, and sandwich properties of component polymers. [15][16][17][18][19][20][21] Besides PANI, biopolymers have been hybridized with other conducting polymers also where the produced materials are extensively utilized for biomedical applications viz. polypyrrole with collagen, 3-butyl sulfonate substitute collagen-pollypyrole, and chitosan-polypyrrole.…”

Mass transport and high barrier properties of food packaging polymers

“…The data correspond to (from bottom to top) the permeation of CH 4 , C 2 H 6 , C 3 H 8 and C 4 H 10 . Drawn after data of Kim et al (2005).…”

Polymeric membrane materials: New aspects of empirical approaches to prediction of gas permeability parameters in relation to permanent gases, linear lower hydrocarbons and some toxic gases

“…Polymers on which data have been taken into consideration include polydienes, polysiloxanes, polyolefins, halogen and silicon-containing carbochain polymers, polymeric esters and ketones, polyamides and polyimides, polyaromatic compounds [3,4,[21][22][23][24][34][35][36][37][38][39][40][41][42][43][44].…”

“…Dependencies of linear C 1 -C 4 hydrocarbons diffusivity as logD on number of carbon atoms in diffusing molecule for PDMS (Δ)[23], PI (⋄)[23], polyvinylallyldimethylsilane (PVADMS,) non-crosslinked (□)[35], PVADMS crosslinked[35] (■), PVTMS (•)[23].…”