Wool fabrics were treated by metalic salts in aqueous solution of about pH7. Cupric nitrate, mercury acetate, zinc sulfate, and silver nitrate were used, and thioglycolic acid was also used. To compensate the charge effects of heavy metallic salts on wool, each treating solution contains KNO3 of the same concentration. The wool fabrics treated with KNO3 is chosen as a blank sample in all experiments. The shrinkage caused by the treatment with metallic salts become conspicuous in the cases of Hg, Ag, and thioglycolic acid. Softness and crease recovery of wool are improved by the treatments with Zn, and Cu. The regain of the zinc treated wool fabrics is almost the same as that of original wool fabrics, while the wettability becomes smaller by all treatments, especially it becomes nearly zero in the case of Hg treatment. The better thermal insulation of the wool fabrics treated with Zn is clearly seen, on the other hand, the thermal insulation of silver treated wool fabrics of the highest shrinkage is smallest among all the treatments. It would be reasonable to suggest that the introduction of silver to wool increases thermal conductivity. The moth proof property is increased by the treatment with Cu, and thioglycolic acid. The shrinkage by washing is smallest in the case of copper treatment.
The effects of the treatments of silk fibroin with heavy metallic salts on absorbability in infrared spectra were studied. Silk fibroin was dissolved in an aqueous solution of LiBr, and the LiBr was removed by dialysis. The fibroin solutions treated with heavy metallic salts under various conditions were dialysed to remove the surplus reagents, poured on polystryrene film and dried at 40°C. All the film of the fibroin thus obtained were found to absorb at 3300, 1660, and 1550 cm-1 in the spectra. Each optical density at 3300, 1660, and 1550cm-1 was shown as DI, DII and DIII respectively and relative densities DI/DII=(A) and DIII/DII=(B) were calculated. The relative densities of original fibroin film DI0/DII0=(A0) and DIII0/DII0=(B0) were also taken. The values of A/A0 and B/B0 were plotted against atomic numbers and electronegativities. Most of the treated films showed lower values of A/A0 than I, and higher values of B/B0 than I, excepting those of treated with zinc and aluminium salts. These facts can be accounted for by considering that hydrogen bond at 3300cm-1 has been destroyed and C=O has been attacked by metallic salts. Optimum conditions are seemed to exist in the reactions of silk fibroin and metallic salts. It would be interesting to note that LiBr which is known as a powerful solvent of silk fibroin reacts with N-H and C=O but probably disturbs hydrogen bond very little.
Acrylonitrile (AN), methyl methacrylate (MMA) and vinyl acetate (VAc) were polymerized in the presence of cellulose acetate. In this study, benzoyl peroxide (BPO) was used as an initiator for radical polymerization. The cellulose acetate was treated with vinyl monomers at room temperature or 60°C. The viscosity of the dilute acetone solution of the products was measured, and the thermal stability of the cellulose acetate fiber treated with MMA was also measured. The results obtained are as follows: 1) AN and VAc do not polymerize so much as MMA. 2) In the case of AN and MMA, Huggins' constant k′ of the dilute acetone solution of the products decrease in comparison with untreated cellulose acetate. However, in the case of VAc, k′ increases a little. 3) The cellulose acetate fiber treated with MMA has smaller thermal deformation than that of untreated cellulose acetate fiber.
Polyacrylonitrile fiber was heated in the temperature range of 200 to 250°C in an inert atmosphere (in the vacuum of 10-4_??_-5mm Hg) and in oxidative atmosphere (in air). The change in the molecular structure with heating was examined by means of X-ray diffractometry, infra-red spectrop-hotometry, electron spin resonance absorption, chemical analysis and measurements of solubility and of amounts of hydrogen cyanide and ammonia formed. From the results of infra-red and elementary analysis, following two types of cyclic systems are suggested to be formed: It seems that the system A, expected to have a plane, sheet-like configuration, is possible to be arranged to form crystallites while the system B, expected to have a kink, twisted configuration, is hardly possible to be arrange to form them. This supposition seems to be supported by the facts that, on the X-ray diffraction curves, a halo corresponding to the diffraction of the (002) plane of graphite apgears at 2θ=26° with heating in the oxidative atmosphere while the halo does not appear at the angle in the inert atmosphere. It is further observed that polyacrylonitrile fiber heated at 250°C in the inert atmosphere is completely soluble in 85% formic acid while the fibers heated at any temperatures in the oxidative atmosphere are not soluble in the acid. This suggests that formation of intermolecular crosslinks occurs only in oxidative atmospheres. Mechanisms on coloration, oxidation, dehydrogeneration and formations of ammonia and hydrogen cyanide are also discussed.
X-ray diffraction curves, densities, number of unpaired electrons, electric resistivities and the amounts of ammonia and hydrogen cyanide formed by heating were measured on flame-proofed polyacrylonitrile fibers (prepared by heating at 300°C in air) heat-treated at various temperature up to 1000°C. Results are as follows: 1) X-ray diffraction intensity of the halo at 2θ=24_??_25° seems to increase with rising of heating temperature. Maximum peak of the halo appears at 25° below 600°C while it appears at 24° above 600°C. 2) Density increases with elevation of heating temperature. It is observed on the density vs. temperature curve that there is a singular point at 600°C. 3) Number of unpaired electrons increases with rising of heating temperature, following a sharp drop above 600°C. Electric resistance tends to decrease markedly above 600°C. 4) Amount of hydrogen cyanide increases with heating temperature up to 800°C. Amount of ammonia also increases with heating temperature, but does not increase above 600°C. It is thought that these results correspond mainly to changes in structure of cyclic systems. Namely, with elevation of heating temperature, the system B which co-exists with the system A in the flame-proofed fiber changes to the system A between 300°C and 500_??_600°C, and further above 500_??_600°C the system C (graphite-type carbon condensed ring) is formed by decomposition and recombination of the system A (or B).
The model slivers with two different counts joined in series were tested by way of experiment as shown in Fig. 1_??_4. When the model slivers were twisted, the distribution of twist for thick and thin parts was measured, and then the tensile properties of the sliver were experimented. From these results for the model sliver, the tensile properties of condensed slubbings were analysed. The results obtained are as follows: In the model slivers, the distribution of twist turns are nearly proportional to the square of counts (Fig. 1, 2). By drafting above twisted model sliver, the thick parts are elongated larger than thin parts. Applying the optimal twist turns, the thin parts shows the minimum elongation, on the contrary the thick parts the maximum elongation (Fig. 3_??_6). On the condensed slubbings, the same results are obtained (Fig. 7_??_10).
The stress recovery of the crimped yarn after the constant elongation for hours was investigated. Parameters taken into consideration are t1 (time required to arrive at constant elongation), ts (during which time elongation is kept at initial length), and tt (during which time elongation is kept at constant elongation). The resluts are as follows. It is apparent that recovery coefficient is lowered with increase of rate of elongation. The rate of elongation in this experiment is lower as compared with that of the ordinary. But recovery coefficient is also lowered with high increase in the rate of elongation in the case of felse-twist method yarn. Then it may be deduced that the recovery coefficient decreases with the rate of elongation. As a quantity of constant elongation is increased. ts the time required to recover initial state is increased. But in conventional-twist method yarn, recovery coefficient is small at lower elongation, because force of crimp friction is larger at lower elongaton in the yarn. Conventional-twist method yarn has a special property in water, because of due to the characteristic condition of heat treatment and shape of crimps.