Preparation of polyethyleneglycol (PEG) and cellulose acetate (CA) blend membranes and their gas permeabilities

Abstract

SYNOPSISMiscible blend membranes containing 10 wt % PEG of low molecular weight 200, 600, 2000, and 6000, and 10 wt %, 20 wt %, 30 wt %, 40 wt %, 50 wt %, and 60 wt % of molecular weight 20,000 were prepared to investigate the effect of PEG on gas permeabilities and selectivities for CO, over N, and CH,. The permeabilities of CO,, H,, O,, CHI, and Nz were measured at temperatures from 30 to 80°C and pressures from 20 cmHg to 76 cmHg using a manometric permeation apparatus. It was determined that the blend membrane, which contained 10% PEG 20,000, exhibited higher permeability for CO, and higher permselectivity for CO, over N2 and CH, than those of the membranes that contained 10% PEG of the molecular weight ranging from 200 to 6000. The high PEG 20,000 content blend membranes showed remarkable permeation properties such that the permeability coefficients of CO, and the ideal separation factors for CO, over N2 reached above 200 barrer and 22, respectively, a t 70°C and 20 cmHg. Based on the data of gas permeability coefficients, time lags, and characterization of the membranes, it is proposed that the apparent solubility coefficients of all CA and PEG blend membranes for CO, were lower than those of the CA membrane. However, almost all of the blend membranes containing PEG 20,000 showed higher apparent diffusivity coefficients for COP, resulting in higher permeability coefficients of CO, than those of the CA membrane. It is attributed to the high diffusivity selectivities of CA and PEG 20,000 blend membranes that their ideal separation factors for CO, over N, were higher than those of the CA membrane in the temperature range from 50 to 80"C, even though the ideal separation factors of all CA and PEG blend membranes for CO, over CH, became lower than those of the CA membrane over nearly the full temperature range from 30 to 80°C.

Preparation and characterization of Matrimid® 5218 based binary and ternary mixed matrix membranes for CO2 separation

“…According to (Loloei et al, 2015) it is approved that although PEG exhibits a strong affinity for CO 2 due to dipole-quadrupole interactions (Yave et al, 2009;Li et al, 1995), further increase in its concentration in polymer matrix (10-20 wt.% PEG) leads to a complete loss of CO 2 /CH 4 selectivity. Increase in PEG content results in enhancing local segmental motions of polymer and a significant increase in CH 4 permeability due to enhanced transport of all gases (Visser et al, 2007).…”

Synthesis, characterization and permeation performance of cellulose acetate/polyethylene glycol-600 membranes loaded with silver particles for ultra low pressure reverse osmosis

“…It was followed by precipitation under controlled evaporation by increasing temperature up to 60°C [22]. The skinned membranes were obtained [23][24][25] which were carefully removed from the glass plates by using a sharp knife. The thickness of the resulting membranes was measured to be in the range of 0.05-0.2 mm.…”

Improved CO2 separation performance of Matrimid®5218 membrane by addition of low molecular weight polyethylene glycol

“…3 . 14,19 Th e T g of PEG shift s from -77 °C to -27.4 °C (higher temperature) for the membranes containing 10 wt.% PEG. As expected, the addition of low molecular weight PEG as an amorphous polymer causes diff erences in the intensity and a slightly position changing of characteristic peaks of pure Matrimid.…”

“…In recent years, the application of polymeric membranes for CO 2 removal from various gas streams has been rapidly growing in gas separation applications. Li et al 19 prepared CA/PEG 20000 blend membranes. [1][2][3][4][5][6][7][8][9][10] In the past decade, polyimides, especially Matrimid®5218, have been commercially used as promising membrane materials for natural gas purifi cation due to their high diff usivity selectivity and favorable chemical resistance and mechanical stability.…”