DIRECT-RADIATION GRAFTING OF ACRYLIC-ACID TO NYLON-6 FABRIC AND THE BEHAVIOR OF THE RESULTING GRAFT COPOLYMER

The role of certain cations as homopolymer inhibitors in the direct ra diation grafting of acrylic acid to nylon-6 fabric was investigated. T he grafting solution was methanol and water at a ratio of 30 : 70 vol% . The maximum graft yield was obtained at 0.08 wt% when using Fe2+ and at 0.7% for Fe3+. In addition, the graft yield obtained with the latt er ion was higher than that for the former. Moreover, the presence of Na+ and K+ salts in concentrations as low as 0.1 wt% caused an increas e in the graft yield. The hydrophilic properties investigated indicate d that the water absorption of nylon-6 fabric after 9 days increased b y 44 times after grafting with poly(acrylic acid) at 166% graft yield. This ratio became 123 times, when this graft copolymer was transforme d to the sodium salt. These ratios became 105 and 490 times for the co rresponding recrystallized forms, respectively. A study was made to ga in a better understanding of the observed super water absorption using SEM and DSC analysis. SEM micrographs of the recrystallized copolymer indicated the formation of large pores with a dendritic structure. Mo reover, DSC showed a decrease in both the heat of fusion and melting p oint. The grafted nylon-6 fabric showed a noticeable affinity for diff erent dyestuffs.