[en] The water vapor sorption--desorption isotherms of graft copolymers of methyl methacrylate with natural and chemically modified wool (i.e., oxidized, reduced, methylated, and crosslinked) have been investigated. As a result of graft copolymerization a reduction in water absorption was observed. The results have also been analyzed in the light of Hailwood--Horrobin equations

[en] The radiation-induced graft copolymerization of methyl methacrylate onto wool fibers and chemically modified (oxidized, methylated, reduced, and crosslinked) wool fibers was investigated in dimethylformamide at room temperature. The homopolymer was separated from the graft copolymer by Soxhlet extraction. The grafting increased with increase in radiation dosage from 0.5 to 1.5 Mrads. The % graft-on depended on the nature of the wool fibers and decreased in the following order: methylated wool, reduced wool, oxidized wool, natural wool, and crosslinked wool. The molecular weights of the grafted copolymer (after separation from the wool fibers) and homopolymers were determined viscometrically. An increase in the radiation dosage reduced the molecular weights of the polymers

[en] X-ray diffraction patterns of the α- and β-crystalline phases of natural, chemically modified, and MMA-grafted wool fibers were investigated. In the grafted fibers variation of the equatorial and meridional scattering intensity during the α-β transformation was inhibited. This indicated that the grafting had stabilized the structure to the α-β transformation. The average crystallite size was found to increase with the extent of grafting, and the degree of orientation appeared to decrease with percent graft-on. SEM studies revealed little damage to the surface topography of wool fibers after chemical treatments. Graft copolymerization with MMA made the fiber surface regular and smooth, mainly because of deposition of polymer in the escarpment, thus reducing the sharpness of the scaly structure. Scanning electron micrographs of the peeled-off surface and cross sections of the grafted fibers indicated that a significant amount of polymer was deposited in the medullae of the fibers

[en] This paper presents, for the first time, conducting films of polythiophene prepared by plasma-polymerization. In this technique, ionized argon is the initiating species for the polymerization of thiophene in a region away from the high RF flux-density. These films displayed a conductivity of 1.8 x 10^-4 S cm^-1 after doping with iodine. The surface morphology of the films deposited away from the high RF flux-density region showed topology similar to the films prepared by electrochemical methods. The films deposited near the high RF flux-density region showed a platelet structure. (orig.)