Enhancement of gas permeability in HPC, CTA and PMMA under microwave irradiation

Gas permeability in hydroxypropyl cellulose (HPC), cellulose triacetate (CTA), and poly(methyl methacrylate) (PMMA) membranes under microwave irradiation was investigated in comparison with permeability obtained without microwave (conventional method). Permeability coefficients for several gases in HPC, CTA and PMMA under microwave were higher than those obtained by conventional methods. That is, the enhancement of gas permeability (microwave irradiation effect) by microwave was made clear, additionally it was suggested that accelerated molecular motion of -OH and -COO- moiety in side chains contribute to the enhancement under microwave irradiation. The degree of the enhancement of gas permeability depended on the combination of polymers and gases. Consequently, the size of gas molecule, polar groups and free volume spaces in polymer are assumed to affect the microwave irradiation effect.