Semi‐IPN asymmetric membranes based on polyether imide (ULTEM) and polyethylene glycol diacrylate for gaseous separation

Abstract

Semi-interpenetrating polymer networks (semi-IPN) formed with commercial polyether imide (ULTEM V V R , PEI) and poly (ethylene glycol) diacrylate (PEGDA) were used to make asymmetric membranes. The effect of increasing amount of PEGDA on the bulk and the gas separation properties of semi-IPN membranes were studied. The formation of IPNs was confirmed by Fourier Transform Infra Red (FT-IR) spectroscopy. The 5% weight loss temperature decreased and the percent weight loss of the first step increased with increase in the PEGDA content, which indicated the incorporation of more poly (ethylene glycol) (PEG) segments to the semi-IPNs. The microscopic experiments revealed the change in morphology with change in PEGDA content. The Scanning electron micrographs exhibited typical finger-like voids in the sub layer, which is characteristic morphology of asymmetric membranes. The increase in PEGDA content up to 5.7 wt % increased the CO 2 /N 2 selectivity of the semi-IPN after which the selectivity decreased and permeance increased. Although, the increase in the polar poly (ethylene glycol) molecules is expected to render better CO 2 selectivity, the performance of the membrane was found to decrease as PEGDA content exceeded 5.7% for the given ratio.

Separation performance of asymmetric membranes based on PEGDa/PEI semi-interpenetrating polymer network in pure and binary gas mixtures of CO2, N2 and CH4

“…A complete description of the materials is given in a previous publication [25]. Aromatic PEI Ultem ® 1000, anhydrous 1-methyl-2-pyrrolidinone (NMP), PEGDa (mol.…”

“…2 and Table 1 respectively. The membrane making process was previously described in detail [25], briefly, the PEI is pre-dissolved in NMP, to which the PEGDa/initiator are then added. Solutions were mixed by rolling until the onset of turbidity, then cast onto a glass plate using a doctoring blade set to 250 m followed by gelation into distilled water at room temperature.…”

“…Recently we have reported the pure gas permeation studies based on semi-IPN membranes of commercially important glassy polymers and poly (ethylene glycol) diacrylate (PEGDa) [24,25]. These IPNs are formed by the crosslinking of PEGDa in a pre-polymerized component (PEI) with no covalent bonding between PEGDa and PEI; hence they fall under the category of sequential IPNs [26].…”

Synthesis and characterization of bis (4-maleimidophenyl) fluorene and its semi interpenetrating network membranes with polyether imide (Ultem® 1000)

“…Despite these salient properties, the permeance of the polyether imides should be substantially increased in order to compete with conventional separation processes. Recently our group reported asymmetric semi-IPN membranes with increased permeance [20][21][22]. Semi-IPN membranes of thermoplastic polymer and bismaleimide (BMI) increased the permeance by a factor of 15 without compromising the selectivity [20].…”

“…This often led to phase separation and inferior gas transport properties. Our group reported a novel synthetic route with increased control over the semi-IPN formation [20][21][22].B M I was polymerized at ambient conditions in the presence of a proton donor, polar aprotic solvent and polyetherimide without the need for an initiator or catalyst [20,21]. At ambient conditions the polymerization occurs at a slower rate and hence it is possible to arrest the reaction at the required stage to control the phase separation and morphology [20,21].…”