The modification of cellulose (cotton fabric or yarn) has been carried out with acrylonitrile under ionizing radiation. Irradiation of the cotton in aqueous acrylonitrile solutions with gamma‐ or electron radiation produces a modified cotton with improved rot and mildew resistance similar to that of cyanoethylated cotton. Strength properties are not significantly affected, provided the radiation dose is less than 5 Mrads. The pickup of acrylonitrile by cotton depends on monomer concentration, dose, and dose rate. It was also observed that water was necessary to give the desired uniform modification. Doses of 0.5–1.5 Mrads produced modifications in the range of 8–15%. Dose rate effects are present at low doses, where pickup decreases with increasing dose rate. Above 5 Mrads, dose rate effects are minimized. Although the data do not show whether actual grafting is occurring with the cellulose, either directly from radiation or through oxidative products formed in the water, or whether the cellulose is being swollen with the aqueous monomer solution which is then intimately polymerized by radiation fragments resulting from the radiation, it is apparent that polymer is formed uniformly upon or within the cellulose structure and that it cannot be removed by solvent extraction. As a result of the modification, the solubility of the cellulose in its usual solvents is decreased and other properties are modified, especially rot resistance, which is improved. Modification of cotton with monomers other than acrylonitrile has also been considered. Pickups of styrene, acrylic acid, methyl isopropenyl ketone, ethyl acrylate, and methyl methacrylate have been obtained from methanol–water solutions.
A series of 2‐nitroolefins was synthesized and polymerized, with particular attention given to 2‐nitrobutene. Several catalysts were compared, and the sodium cyanidedimethylformamide system studied in detail. Monomer aging had a pronounced effect on the polymerization of the nitromonomers. The polymerization under ideal conditions is exceedingly fast, and evidence favors chain termination by chain transfer to monomer. Molecular weights, even under optimum conditions, were low, and solvents with high dielectric constants were ordinarily necessary for polymer formation. The effect of chain length on polymer properties was also determined.
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