چكيده لاتين :
The effects of chain extender length on the gas permeability of polyether-based
polyurethanes were investigated. Synthesized polyurethanes were based on
1000 and 2000 molecular weight polytetramethylene-glycol (PTMG) with toluene
diisocyanate (TOI). Ethylene glycol, 1A-butane diol (BOO), 1,6-hexane diol (HOO) and
1,1O-decane diol (000) chain extenders were used to complete the conversion of prepolymers
to the final polyurethanes . Membranes made from polyurethane were used to
study the permeability and diffusivity of nitrogen, oxygen, methane, and carbon dioxide.
Lag time method was used to determine the diffusivity of gases in polyurethanes.
This study indicated that glass transition temperature of the polymers decrease by
chain extenderיs length. The increase in chain extenderיs length makes the phase separation
more probable. OSC and FTIR studies also indicate the extent of the phase
separation in polyurethanes. Permeability and diffusivity of gases increase with the
increasing length of the chain extenders. Selectivity of CO2/N2 changed by chain extender
length, while selectiv ity of CO2/CH4 and 02/N2 did not show any remarkable
changes. This study shows that solubilization is the dominant mechanism in gas permeation
process in polyurethane membranes.
