Block Copolymers and their Blends with Polyethylene Glycol

3 Block Copolymers and their Blends with Polyethylene Glycol 

It has been observed [24] that for PEG (200g/mol) modified Pebax membrane for CO2 separation the CO2 permeability increased by a factor of about 2 (from 73 to 151 Barrer) and the separation factor CO2/H2 also increased by PEG addition (50 wt.%). This enhancement was attributed to the appearance of additional ethylene oxide (EO) units and free volume increase. Higher content of EO units results in an increase in the solubility of CO2. Later, the total free volume increase and hence the increase of the permeability was demonstrated by measurements of density and by positron annihilation lifetime spectroscopy (PALS) analysis [75]. 

Source Reprinted with permission from Advanced Functional Materials, Tailor-made polymeric membranes based on segmented block copolymers for CO2 separation, by A. Car, C. Stropnik, W. Yave, K.-V. Pelnemann, 23, 

The enhancement of permselectivity, solubility selectivity and diffusivity selectivity of 4000PE055PBT45/PEG blend membranes are presented in Table 12.4. The successful 

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