Effects of bromine substitution on the physical and gas transport properties of five series of glassy polymers

The effects of bromine substitution on the physical and gas transport properties were examined for five families of tetra-substituted glassy polymers: bisphenol A polycarbonates (PC), hexafluoro-polycarbonates (HFPC), hexafluorobisphenol- tertiary butyl isophthalates (HFBP-tBIA), fluorenebisphenol-...

Full description

Saved in:

Bibliographic Details
Published in:	Polymer (Guilford) Vol. 40; no. 12; pp. 3367 - 3382
Main Authors:	McCaig, M.S, Seo, E.D, Paul, D.R
Format:	Journal Article
Language:	English
Published:	Oxford Elsevier Ltd 01-06-1999 Elsevier
Subjects:	Applied sciences Bromine substitution Exact sciences and technology Gas transport properties Miscellaneous Organic polymers Physical properties Physicochemistry of polymers Properties and characterization Physical properties Gas transport properties Bromine substitution Substituent effect Isophthalate polymer Transport properties Gaseous diffusion Fluorine containing polymer Ester polymer Aromatic polymer Bromine containing polymer Experimental study Cardo polymer Gas permeability Glassy polymer Selective permeability Polycarbonate Activation energy
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The effects of bromine substitution on the physical and gas transport properties were examined for five families of tetra-substituted glassy polymers: bisphenol A polycarbonates (PC), hexafluoro-polycarbonates (HFPC), hexafluorobisphenol- tertiary butyl isophthalates (HFBP-tBIA), fluorenebisphenol- t-butyl isophthalates (FBP-tBIA) and bisphenol A- t-butyl isophthalates (BPA-tBIA). Additionally, the thermal response of the substituted BPA-tBIA polymers was explored to elucidate the effects of bromine substitution on the activation energies of permeation and diffusion and on the heat of gas sorption. Compared to its methyl-substituted analog, each bromine-substituted polymer had a higher cohesive energy density, a higher glass transition temperature and a lower oxygen-specific fractional free volume. Bromine substitution significantly reduced O 2 and CO 2 permeability and substantially increased both O 2/N 2 and CO 2/CH 4 selectivity. An increase in the activation energy of diffusion for N 2 compared to O 2, and for CH 4 compared to CO 2, may be credited for the majority of the selectivity gain. A new method for evaluating penetrant-dependent fractional free volume proved to be a valuable tool in determining the effects of structural changes on gas transport behavior.
ISSN:	0032-3861 1873-2291
DOI:	10.1016/S0032-3861(98)00570-9