Dynamic viscoelastic properties were measured on several regenerated fibers by means of the vibrating reed method within the frequency range from 50 to 170 cps., in order to make clear the relation between the viscoelastic properties and the internal structure such as crystalinity, size of crystalite, orientation and network structure.
The results obtained were as follows:
1. The orientation of molecules in the crystal or amorphous region had profound influence on the dynamic viscoelasticity of fibers. Dynamic modulus (E₁) and dynamic loss (E₂) increased with the orientation, however loss tangent (tanδ) was almost independent of the orientation.
2. The growth of crystalines and the increase of networks in amorphous region made increase of E₁, which might be due to the increase of intermolecular bonds. E₂ and tan δ decreased with those change in fine structure. It could be assumed that the region sensitive to E₂ had decreased within the frequency region covered.
3. When the degree of polimerization decreased, E₁, and E₂ also decreased, but tan δ increased perhaps as the result that the degradation of molecular chains was more effective to the decrease of E₁ than to the decrease of E₂.

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In this report, the effects of Co⁶⁰ gamma-ray in the visco-elastic properties of textile materials have been measured. The result is as follows.
Saran shows degradation and with the increase of irradiation dose, the dynamic modulus decreases and with the melting of fine crystallites the dispersion peak of loss-tangent shifts to lower temperature and the height of the peak becomes lower.
Nylon 6 shows an increase of dynamic modulus up to the irradiation of 5×10⁷ rep at room temperature and shows a decrease at 10⁸ rep compared with unirradiated sample. As the irradiation dose increases, α′-peak of loss-tangent of nylon 6 shifts toward lower temperatures and height of the α′-peak becomes lower and at 10⁸ rep α′-peak increases remarkably compared with the unirradiated sample. Therefore, upto the irradiation dose 5×10⁷ rep, the cross-linking effect dominantes in nylon 6 and its degradation effect appears on the irradation dose 10⁸ rep.
Crystalline polyethylene terephthalate showed an increase of dynamic modulus with an irradiation dose upto 10⁸ rep and the peak of loss-tangent which appeares at glass transition temperature of polyethylene terephthalate showed change almost no. Therefore, it may be conceived that this is an annealing effect due to irradiatin and there is no relationship with cross-linking and degradation.

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The effect of twist on some mechanical properties of three single continuous-filament yarns of glass fiber were investigated, observing the stress-strain curves, yarn diameter and retraction.
The stress-strain curve of the twisted glass yarns was a simple straight form; the tensile strength of each yarn decreased gradually with twist and could be expressed by Platt's equation. The breaking extension was almost constant except strong twisted region. Increasing the twist at the constant loading, the yarn diameter decreased first and after the certain twist it retained the constant value.
The retraction and breaking twist angle were not affected by the fineness of the filament and the sizing materials on the glass filament surface; they were only dependent on the yarn diameter.

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As the fabric is an assembly of the yarns, its mechanical properties depend upon not only the yarn properties but also the form of the yarn axis in the fabric. Ordinarilly, this yarn axis form was approximated by many workers by sine wave or a curve, which is a continuity of arc and straight line. But sine wave is determined only by amplitude (a) and wave length (4l). And this mathematial treatment is not practical. Real yarn axis in the fabric has various curved forms under the same amplitude and wave length. In this paper, a quarter of crimp of yarn axis is assumed by the form:
For the various values of parameter n, differential curved form are obtained (as shown in Fig. 2).
The crimp ratio p depends upon a/l and n, and p is obtained by the equation (15) and (19) for na/l_??_1 and na/l_??_1 respectively. The relationship between p and a/l for various n is shown in Fig. 5. The usefull equation required for p is obtained by rough approximation in the equation (23).
The theory for the yarn axis is applied to the fabric and crimped fiber.

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The creep behavior of Lincoln wool fiber in water is studied by varying temperature (from 10°C to 97°C.), stress (from 9 to 55×10⁷ dyne/cm²) and initial extension rate (from 70 to 300%/min.). There are two difficulties in the creep experiment. The first is that constant static stress could not be applied instantaneously, and the second is that the creep strain within a few seconds may not be measured accurately. In this experiment, the creep strain can be magnified by optical lever technique (Fig. 1) and 0.001mm, deformation is detected by the cinematograph which projects the scale. The instantaneous strain at 0.1 second can be measured.
The results of this experiment are as follows:
(1) The instantaneous strain depends upon the rate of loading. The higher the speed of extension under the same load, the lower the instantaneous strain.
(2) According to the successive creep and its recovery tests, the creep curves nearly coincide with each other after several repeated tests.
(3) The length of the fiber is well reversible from creep test under 2% extension (in Hookean region) in water. The specimen is more completely recovered at a temperature higher than that of the creeping temperature. The fiber, although, contracts after creep test under low extension above 60°C. It is suggested that supercontraction and permanent set depend upon the amount of broken and re-formed hydrogen or polar bonds. The creep recovery from high extension is not sufficient during short time (15min.) below 60°C.
(4) Beyond the yield point, the instantaneous strain increases remarkably with rising of the temperature, whereas a little decrease of Young's modulus is obtained in Hookean region.

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Red pine wood chips extracted with alcohol-benzene were cooked by the neutral sulphite process and made into pulps. Then out of pulps were made “prepared” lignins with sulphuric acid of various concentrations. The content of methoxyl group in the lignin was determined. The content of sulphur and of methoxyl group and the chlorine number by Okada's method of the pulps were determined.
(1) In the first report we had assumed that the carbohydrate in pulp should contain some methoxyl groups. From the experimental results in this report, however, we could not confirm the assumption.
(2) It was impossible to determine the sulphonated lignin in the pulp by the sulphuric method, since some parts of lignin dissolved during the determination.
(3) The chlorine number of pulp determined by Okada's method was suitable to denote the content of lignin in pulps.
(4) It was found that the lignin contained in woods, semichemical pulps and chemical pulps did not differ in methoxyl group/lignin ratio.

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To study the relation between the moisture regain and the heterogenity of the nitration process in the fibrous state, the effects of the composition of the nitrating mixture, time and temperature of reaction on the swelling at reaction, the nitrogen content of the product, its moisture regain etc, were determined.
The results are as follows:
(1) A carbon tetrachloride (or acetic acid)-acetic anhydride-nitric acid system was suitable to study the process because of its mild reaction and little damage to the fiber.
(2) When the water content of the raw material exceeded 30%, the nitration was accelerated considerably.
(3) The rate of nitration increased with higher temperature.
(4) When this system was diluted over 1:9 with carbon tetrachloride, the nitration was retarded.
(5) In the acetic acid-acetic anhydride-nitric acid system, less acetic anhydride gave higher swelling at the reaction and more rapid reaction.
(6) Higher swelling at the reaction, which was derived from higher sample moisture etc., seems to result in lower moisture regain of the product at the same nitrogen content. It is suggested that the reaction proceeds macro-(fiber)-homogeneously and micro-(crystallite)-heterogeneously and that the hydroxyl groups in the amorphots region, which mainly absorbes the moisture, can be substituted selectively.

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In order to improve the dyeability of vinylon, the wet spinning of a polymer blend consisting of polyvinyl alcohol and a polymer containing vinyl pyrrolidone units, such as polyvinyl pyrrolidone and saponified or unsaponified vinyl acetate-vinyl pyrrolidone copolymer was carried out, and the fiber was subsequently heat-treated and acetalized to make the fiber resist to boiling water. Consequently, the fiber having improved dyeability with several dyes such as direct dyes, sulphur dyes and vat dyes, similar to that of cellulosic fibers, was obtained. The effect of blending of polyvinyl pyrrolidone may be explained by the affinity of the dye for polyvinyl pyrrolidone and by the known changes in the cross sectional structure and in the internal fine structure due to the polymer blending. The fiber may be suitable for blending with cellulosic fibers.
By hot-drawing the wet-spun fiber containing polyvinyl pyrrolidone, followed by heat-treatment and formalization, the fiber having a relatively higher stiffness and the improved dyeability was obtained. The fiber shows the stiffness-dpeabillity relation similar to that of a cotton fiber, so the fiber seems to be suitable for blending with cotton.

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The solubilities of Methyl Orange at various conditions have been obtained, and the relations between activity factor and adsorption of Methyl Orange by cellophane sheet have been studied.
The activity facter is calculated from the following equation; where, f, k_s, [Na⁺] and [D^-] are mean activity coefficient of dye solution, solubility product constant, sodium ion concentration and dye ion concentration respectively.
In this paper, the following results have been obtained.
1. The reciprocal of square of activity factor is proportional to the concentration of sodium ion added in the solution.
2. Amounts of adsorbed Methyl Orange by cellophane sheets (direct dyeing) are proportional to the reciprocal of activity factor of the dye in the solution.

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Stearyl, cetyl, myristyl and lauryl chloroformates were prepared by the phosgenation of the corresponding alcohols in benzene. Their identifications were made by the preparation of respective urethanes.
N, N-ethylene higher alkyl urethanes were synthesized by the condensation reaction of higher alkyl chloroformates with ethylenimine in benzene using triethylamine as an acid acceptor. Crystalline N, N-ethylene urethanes such as stearyl or cetyl were identified by N analysis of thier own, while non crystalline ones (not isolated) were confirmed by the preparation of thiophenol adducts.
Viscose rayon fabric treated by the dispersion of N, N-ethylene stearyl urethane showed the best water-repellency, and from this result, it is expected that N, N-ethylene stearyl urethane would be very interesting in the practical use.

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N, N-ethylene higher alkyl urethanes were prepared by the reaction of higher alkyl chloroformates and an aqueous solution of ethyleneimine using sodium or ammonium carbonate as dehydrochloric acid agent, in the presence of a small quantity of non-ionic surface active agent under cooling and stirring. N, N-ethylene higher alkyl urethanes prepared in water as dispersion were separated and identified respectively.
N, N-ethylene stearyl urethane prepared in water was submitted to the finishing test on rayon fabric, with or without an urea-melamine-formaldehyde resin. The fabric after finishing possessed a durable and washable water-repellency.

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The paste of N, N-ethylene stearyl urethane was prepared by heat dispersion method in consideration of its industrial manufacturing.
Viscose rayon fabric was treated on an industrial scale by the current resin finishing solution adding the dispersion of N, N-ethylene stearyl urethane prepared by the heat dispersion method.
The treated fabric showed a durable water-repellency as well as improvement on flexing abrasion resistance, tensile strength and tear strength.

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