Optical behaviours of cross sections of model “fresh” cellulose filaments, coagulated freely with various compositions of the bath, were examined with a polarizing microscope and the orienting effects of compression caused by shrinkage during coagulation are discussed. The orienting effects of compression are distinctly dependent on the composition of the coagulating bath and, consequently, on the course of coagulation. The more strongly gelatination takes place before regeneration, the less the orienting effect show up. Then the orienting of compression is exhibited more remarkably in the β-type coagulation, such as those by Na+ or H+, than in the α-type coagulation, such as that by Zn++. When the multilayer structure consistedy of the alternative succession of α-and β-layers is formed by the bath similar to Müller bath, the radial gradient in orientation shows an intermittent distribution.
Though a benzalized polyvinyl alcohol fiber shows fairly high elastic recovery, it has a drawback of very poor acid resistance. In order to obtain a resilient and acid resistant fiber, heated polyvinyl alcohol fibers were acetalized with some benzaldehyde derivatives obtained by substitution of chloro-, nitro-, or cyano-group into the benzene ring, and aliphatic aldehydes having a benzene ring or an alicyclic ring. And benzaldehyde and formaldehyde were also used for the control. On these acetalized fibers, the acid resistance, elastic recovery, and other properties were examined. Concerning the acid resistance, the formalized fiber is the best, the benzalized fiber and tolualdehy-de-acetalized fiber belong to the lowest class, and the others are generally intermediate between the above two groups. Among three fibers acetalized with o-, m-, or p-chlorobenzaldehyde, the ortho shows the best acid resistance, the meta is the medium, and the para is the lowest. The resistance of 2, 4-dichloro-, m-nitro-, p-nitro-, p-cyano-, or p-chloro-m-nitro-benzaldehyde-acet-alized fiber is almost same as that of the o- chlorobenzalized fiber. The effects of various substitutions into the benzene ring in benzaldehyde on the acid resistance seem to be almost parallel to Hammett's σ-constants. The fibers acetalized with benzaldehyde derivatives substituted by electronegative groups have almost similar wet- and dry-heat resistance, tenacity, breaking elongation, and elastic recovery, and fairly superior acid resistance to the benzalized fiber. In the case of aliphatic aldehydes, such as phenylacetaldehyde, and tetrahydro-, and trimethyltetrahydro benzaldehyde, a better acid resistance is obtained than in the benzalized fiber. The results on the acid resistance of acetalized fibers seem to be explained by the mechanism in the hydrolysis of acetals shown by O'Gorman and Lucas.
After a polyvinyl alcohol filament was emerged from coagulating bath, it was drawn in wet state, in hot air, or in wet state and then in hot air. The maximum draw ratio and the maximum tenacity were obtained when the filament was drawn in hot air, or in wet state and then in hot air. The relation between tenacity ratio of drawn filament against the undrawn and the draw ratio is expressed by a straight line which passes through the original point, independent of the various drawing methods used. In filament which emerged from the coagulating bath at relatively lower velocity, the slope of the line is about 0.8. The relation between breaking tenacity and elongation is also expressed by a single curve independent of the drawing methods. As the emerging velocity is increased, tenacity at the same elongation and the maximum tenacity decrease.
1) Some characteristic colour reactions were found when the reduced wool was immersed in acidic nitrite solution. Nitrosofication which brings yellow colouration was preceded by red colour reaction due to the reaction between nitrite and sulfhydryl groups of free reducing reagents or cysteine residues in the reduced wool. On strong acid side, the reduced wool turned into orange with the progress of nitrosofication. In acetic acid solution, therefore, this nitrite treatment is applicable for a convenient method of the qualitative detection of sulfhydryl graups in wool. 2) Although bisulfite never coloured up with nitrite, wool reduced by this reducing reagent showed slight red colouration. owing to the appearance of sulfhydryl group in the acetic nitrite treatment. When wool was reduced in sulfite solution, however, no red colouration was recognized. 3) Colouration was affected by acidity of the reduced wool. Nitrite reacted more easily for the wool reduced on acidic side than on the basic. On the other hand, actions of hydrogen peroxide for them were in contrast. 4) On acidic side, the nitrite treatment for the reduced wool brought the decreases of its phenol-shrinkability and alkali-solubility. Although it seems that they owe to the increase of covalent bonds or hydrogen bonds in it by nitrosofication, deamination, diazotation and rebuilding of cystine bridges, the increase of stability arose from the masking its sulfhydryl groups by this treatment cannot also be ignored.
A first creep and recovery behaviors of commercial Terylene filament in long duration test for 24 hr were studied under the various loads at 20°C. and 54% RH, and also a second creep and recovery test for 24 hr were made under the same condition. The following results have been recognized; 1) With the exception of the highest load of 3.0g/d, the relationship of strain versus log. (time) is found to be nearly linear in the first and second creep tests, and then the strain rises by increasing the load. On the other hand, total recovery curves are concave to the log. (time) axis under the higher load, and cenvex under the smaller. 2) For the smaller load, initial deformation is larger in first creep than in the first recovery, and for the higher load, its relationship becomes reversed. However it is always larger in the second creep than in the recovery. 3) For the smaller load, the delayd deformation rises slowly as the load is increased, but in the load from 1.0 to 2.5g/d the increased load does not affect it. Fig. (6) shows that the delayed deformation rises rapidly under the highest load of 3.0g/d. It may be attributed to the effect of the flow deformation. 4) On the first and second tests there is a load which minimized the residual deformation, and that of the second test was found smaller. For the some higher load, the recovered specimen's length is shorter than the original, and not contraction is smaller on the second test. 5) Total deformation e is plotted in Fig. (8) according to Andrade's equation [γ=γ0+βt1/3]. With the exception of within 3 min. from start, the creep curves to the above formula, The relation between instantaneous elongation γ0 and the stress is almost linear. Parameter β rises very rapidly as the load is increased on the first creep, and slowly on the second creep. Equation β=β0sinαS is found most suitable for the β-S curves.
The causes of Set Mark and the relation of weaving conditions with it in acetate fabrics are studied by weaving under several loom settings. It is found that Set Mark is caused by the relation between relaxation in warp yarns and beating effect. The conditions of eliminating Set Mark are decided from the results of our experiments; to form a straight warp line, to restart the loom within 5 min, and to stop the loom at 330 degrees crank angle.
The effect of gamma radiation on the physical properties of P. V. C. fibers were investigated. The following results were obtained; 1) Tenacity, specific gravity, and viscosity of the irradiated samples were decreased with irradiation 2) Extinction coefficient of P. V. C. solutions was increased. 3) Preciously heat decomposed fibers which had polyene structure showed resistance against the radiolysis. 4) By heating the irradiated fibers the property against the thermal schrinkage had shown improvement even by the small dosage. This fact might be explained by the end-linking due to the radiation-induced radicals.
The mechanism for explaining how crease recovery was imparted to viscose rayon fabrics using urea formaldehyde resin, was studied by measuring the mutual relation between the physical properties such as crease recovery, imbibition value and elastic recovery of the viscose rayon fabrics treated with dimethylol urea solution and the changes in these properties by repeated soaping. The following results were obtained: 1) Compared with the case of formaldehyde treatment, the increase of elastic recovery was relatively small and presumably not to be caused by the formation of the cross linkage between resin and cellulose. Perhaps improvement of crease recovery of the treated fabrics was caused by the deposit of resin within the fiber. 2) The surface resin, easily removed by soaping, also contributed to improve crease recovery in the limited amount of content, as well as the fixed resin within the fiber.
In practical dyeing, the dyebath is not always maintained at a constant temperature for a whole period of dyeing, but the temperature of the dyebath is raised slowly from a low to a certain high temperature and is maintained at that temperature. In this report, first the rate-of-dyeing equation raising temperature in the finite dyebath, is obtained theoretically on the restricted conditions by using the solution of the diffusion equation for the infinite dyebath obtained by Crank2). Secondly, the formula of calculation of the rate-of-dyeing raising temperature in the finite dyebath is derived from Vickerstaff's hyperbola equation. Then the calculated curves are compared with experimental values obtained by dyeing 6-nylon yarns with disperse dyes. Thirdly, using Duhamel's theorem, the rate-of-dyeing equations for the finite dye-bath obtained by Wilson1) and Crank2), are derived from those for the infinite dyebath obtained by Hill5) and Crank2).
The effects of polymer-electrolyte solution in direct dyeing were studied from the view points of the equilibrium adsorption and the diffusion coefficient of dye within the fiber. The followings were used; Polymer-electrolytes-Sodium Alginate and Sodium Carboxymethyl Cellulose, Dyestuffs-Direct Scarlet B and Chrysophenine G, and Fiber-Viscose Rayon Staple. The results are 1) In direct dyeing, cations dissociated from polymer-electrolyte act as well as those from inorganic electrolyte.-effect (1). 2) Adversely, polymer-electrolyte adsorbs direct dye itself, therefore, apparent concentration of dye in solution decreases and dye adsorbed on fiber decreases, too.-effect (2). 3) Increased salt concentration decreases effect-(1) and increases effect-(2). 4) The reciprocal correlation between effect-(1) and effect-(2) makes characteristic change of the equilibrium adsorption and the diffusion coefficient.