Polymers

Gas and vapor transport plays a key role in separations using polymeric membranes, but limiting these processes is also critical for developing effective packaging materials. Equilibrium sorption isotherms and kinetic measurements can provide crucial information, as a function of both temperature and sorbate concentration. Thermodynamic parameters and kinetic properties, such as activation energies and diffusivities, can be obtained by fitting data to appropriate models.

Of increasing interest recently are microporous organic polymers. Such materials include polymers of intrinsic microporosity (PIMs), conjugated microporous polymers (CMPs) and porous aromatic frameworks (PAFs). Assessing these for gas storage and separation applications requires measurement of their gas adsorption properties at relevant gas pressures and operating temperatures.

Different Hiden Isochema instruments can be used for such studies. For example, the IGA-001 can measure gas sorption – both gas solubilities in non-porous polymers and gas adsorption in porous polymers – while the IGA-002 can measure both gas and vapor sorption over a range of pressures and temperatures. Our XEMIS sorption microbalance can be used to further extend the range of species and pressures. IGAsorp instruments, meanwhile, can be used to determine moisture vapor transmission rate (MVTR) through film packaging and polymeric membranes.