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SynopsisT h e alkali hydrolysis of poly(ethy1ene terephthalate), anionic copolymer of poly(ethy1ene terephthalate), and block copolymer of poly(ethy1ene terephtha1ate)-poly(ethy1ene glycol) is investigated under a variety of conditions of alkali concentration in aqueous bath, additives, time, and temperature. Measurements of loss in weight, linear density, breaking load, tenacity, elongation to break apart from intrinsic viscosity, fiber density, COOH-end group content, diameter of filaments, and scanning electron micrographs have been analyzed to identify the differences in the action of alkali on these polymer materials.

The dyeing behaviour of a number of dye mixtures on three types of fibre has been studied by the method based on assessment of colour build up under practical dyeing conditions, as well as under ideal conditions. Some a*b* and L*C*ab diagrams are constructed for both the conditions. These diagrams give valuable information about the dyeing behaviour of the dye mixtures. The technique reported in this paper will prove useful to a practical dyer for determining the compatibility of dyes in mixtures.

Cotton cellulose dyed with direct cotton dyes was oxidized with buffered sodium hypochlorite solutions under different conditions. An attempt was made to correlate the extent of degradation of cellulose and the oxygen consumption during oxidation with the chemical constitution of dyes. The behavior of dyed samples during exposure to Fade-Ometer light has also been examined to study the influence of the constitution of the dyes. The results are discussed with a view to correlating the behavior of these dyes with that of leuco vat dyes under similar conditions.

The load-elongation values of individual filaments in a multifilament yarn were studied. The behavior of individual filaments in a bundle is not the same as that of filaments tested individually; therefore, the load-elongation diagram of a multifilament yarn has to be used to arrive at tenacity values of individual filaments in a yam. A technique for obtaining load-elongation values of individual filaments was developed using the breaking steps in a load-elongation diagram of a multifilament yam. Preliminary results are described.