Hydroxyethylmethacrylate (HEMA) is considered to be one of the important vinyl monomers. The ability of polyhydroxyethyl-methacylate (PHEMA) graft sites to consecutive chemical modification makes the use of nylon-6 fibers grafted with PHEMA a feasible bed for immobilization of a wide range of biologically active reagents, specially enzymes, drugs, cells, and immunadsorbents. Stemming from the above discussions, in this article, the graft copolymerization of HEMA onto modified nylon-6 fibers containing Polydiallyldimethylammonium chloride (PDADMAC) in the presence of Cu 2þ -K 2 S 2 O 8 as a redox initiating system was carried out, with very high rate and almost without homopolymer formation. The factors affecting the grafting reaction (monomer, K 2 S 2 O 8 and cupric ion concentrations, the amount of PDADMAC as well as the reaction temperature) were studied. Kinetic investigation revealed that the rate of grafting (R p ) of HEMA onto modified nylon-6 fibers is proportional to [HEMA] . The overall activation energy was calculated (71 KJ/mol). The fine structure, surface topography, thermal and electrical properties of parent and grafted nylon-6 fibers were investigated.

A simple, efficient, and practically applicable functional approach for improvement antimicrobial properties of nylon-6 fabrics and increase the washing durability of biofunctions was developed. This finishing approach is based on grafting of the fabrics with methacrylic acid (MAA) to create additional carboxylic groups in nylon-6 macromolecules, followed by subsequent reaction with dimethylalklbenzyl ammonium chloride (DMABAC) solution under alkaline conditions. The carboxylic groups react with cationic agent through ionic interaction, which led to the immobilization of QAS on nylon-6 fabrics. This immobilization was proofed through determination of nitrogen content, applying scanning electron microscopy (SEM), and FTIR microscopy. The effect of treatment conditions on salt uptake (SUT) on nylon-6 fabrics and reaction efficiency (RE) was investigated. The antimicrobial assessment of regular and grafted with PMAA nylon-6 fabrics treated with DMABAC revealed that both types of fabrics are characterized before washing, by quite strong biocide effect on Bacillus mycoides, Escherichia coli and Candida albicans. The role of grafting nylon-6 fabrics before treatment with salt on durability of antimicrobial functions seems to be more significant as the samples were repeatedly washed. Even after Laundring 10 times the grafted samples could still provide 80%, 100%, and 87.5% microbial reduction against B. mycoides, E. coli and C. albicans, respectively, in contrast with 42.6%, 65.6%, and 42.5% in case of regular nylon-6 fabrics.

ABSTRACT:The graft copolymerization of glycidylmethacrylate (GMA) onto modified nylon-6 fibers containing polydiallyldimethylammonium chloride (PDADMAC) groups in the presence of (Cu 2ϩ -K 2 S 2 O 8 ) as a redox initiating system was carried out, with very high extent and almost without homopolymer formation. The mechanism of the graft polymerization induced by this system was suggested. The rate of grafting was determined by varying the monomer, K 2 S 2 O 8 , and cupric ion concentrations as well as the amount of PDAD-MAC. The kinetic investigation revealed that the rate of grafting (Rp) of GMA onto modified nylon-6 fibers is proportional to [GMA] . The overall activation energy was 134.7 kJ/mol. The fine structure and thermal properties of the grafted nylon-6 fibers were investigated.

SynopsisGraft polymerization of acrylic acidhtyrene mixtures on poly(ethy1ene terephthalate) fibers using HzOz as initiator was investigated under different conditions including acrylic acidhtyrene ratio, monomer mixtures concentration, initiator concentration, polymerization temperature, pH of polymerization medium, addition of metallic salts, and use of solvent/water mixture instead of aqueous medium. It was found that the rate and extent of grafting for acrylic acidhtyrene mixtures were much higher than those of single monomers, indicating a synergestic effect. Maximum percent grafting occurred when acrylic acidhtyrene mixture at a ratio of 30:70 was used. Increasing the monomer mixture concentration from 2% to 40% was accompanied by a significant enhancement in percent grafting. The latter increased also significantly as the H202 concentration increased from 10 to 150 meqb, a further increase in HzOz concentration decreased grafting. No grafting took place at 65OC even after 4 h. Raising the polymerization temperature to 75°C expedited grafting; the magnitude of the latter increased by increasing the temperature up to 95OC. Addition of copper sulphate and ferrous ammonium sulphate to the polymerization system offset grafting, the opposite holds true for lithium chloride provided that its concentration does not exceed 15 mmoleb. Methyl alcohol/water mixture (2080) constituted the optimal medium for polymerization. Grafting of acrylic acidhtyrene mixtures to poly(ethy1ene terephthalate) fibers resulted in considerable improvement in moisture regain of the latter.

SynopsisGraft polymerization of 2-methyl-5-vinylpyridine (MVP) onto polyester/wool blended fabric was carried out using benzoyl peroxide as initiator. The graft polymerization reaction was conducted under a variety of conditions. The graft yield increased by increasing benzoyl peroxide concentration from 0.559 mmolefl. to 1.657 mmoieA. Further increase in benzoyl peroxide concentration (i.e., up to 2.795 mmolefl.) decreased grafting. Increasing the M W concentration from 4% to 10% caused a significant enhancement in grafting. The same held true for raising the polymerization temperature within the range of 65O-85OC. The grafting reaction proceeded initially at a fast rate and decreased with time to a slower rate. The grafted samples showed improved dyeability toward acid dye, increased density, and decreased moisture regain as compared with the untreated blend. Furthermore, a tentative mechanism for initiation of grafting was suggested.