SOME PROPERTIES OF HYDROPHILIC POLY(ETHYL ENE-TEREPHTHALATE) MODIFIEDBY GRAFTING WITH POLY(ACRYLIC ACID) FOLLOWED BY SALT FORMATION WITH NA SALTS OF SEVERAL AMINO-ACIDS

Poly(ethylene terephthalate) (PET) was modified by grafting with poly( acrylic acid) (PAA) followed by salt formation with amino acids contai ning sodium carboxylate, hydroxyl and/or hydrophobic alkyl groups. Moi sture regains and numbers of water molecules adsorbed in the monolayer state on each functional group of the modified PET were more than tho se for the Na salt of PAA-grafted PET, but increased not exactly in pr oportion to the amounts of adsorbing sites for water molecules in the salts. The water vapor transmission of modified FIST fabrics apparentl y showed no change in comparison with that of the original PET. Howeve r, taking into account the changes in thickness and in porocity percen tage of the fabrics due to the treatment, the water vapor transmission of PET modified by grafting (17.5%) or by Ca or Na salt formation was two times that of PET, and PET modified with Na salts of several amin o acids was two and a half times that of PET. Dynamic contact angles d ecreased and tendency of wetting of the modified PET increased with in creases in grafting of PAA and in ionization tendency of metals in the salts.