series of silicon-containing polyaramide were synthesized by methodof interfacial polycondensation

and the relationship between their chemical structure and gas transport property was discussed. It is found that the permeability forgases used in this experiment

which is hydrogen; oxygen; nitrogen; carbon dioxide; and methane

is fit for ordinary glassy polymer. Gas permeability increases byintroducing flexible segment into rigid polymer chain. Polyaramide with easily rotational backbone has higher gas permeability

For two polymers with the same backbone

gas permeability is higher for one with methyl side group in its aroma-tic ring. The polyaramide with phenyl side group on silicon atom has higher dif-fusivity

but lower solubility than that with methyl side group on silicon atom. These results indicate that in addition to intrachain motion

interchain spacing difference is a contributing factor in understanding various transport behavior of gas through these silicon-containing polyaramide.