The thermal stress with polypropylene monofilament drawn in hot state is measured preventing from any shrinkage. The stress-temperature curve shows that thermal stress increases at first and then decreases with temperature.
The maximum thermal stress may be inferable to be the force which is a restrictive condition with manufacturing the polypropylene to fiber form. The stages of experimental processes taken may be explained by the following:
1. When the temperature coefficient of thermal stress is positive, the frozen strain is gradually removed.
2. In the case of heating the sample at various constant temperatures, each thermal stress has almost the same maximum value.
3. Voigt model is suitable for these explanations, and the activation energy is calculated from the equation; Where S_T is thermal stress at T°C, S₀ the maximum stress, t heating time and τ relaxation time.
4. The obtained value of activation energy is nearly equal to that of viscous flow.
5. When the temperature coefficient of thermal stress is negative, the relaxation of restrictive force by heat appears.

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Effsects of some ions on the mutual diffusion of NaOH-H₂SO₄ system through a cellophane film as a basic study on the spinning mechanism of viscose were studied and the following results were obtained:
(1) S^-- ion in the alkali solution and Zn⁺⁺ ion in the spin bath solution restrict the diffusion of the spin bath components into the alkali solution and allow the diffusion of the alkali components into the spin bath solution.
(2) The restrictive effects of the diffusion of the spin bath components into the alkali solution by some metalic ions in the spin bath solution have a relationship with the precipitating pII of these metalic sulfides or hydroxides, in the order of Mg⁺⁺, Fe⁺⁺⁺, Al⁺⁺⁺, Mn⁺⁺, Fe⁺⁺, Zn⁺⁺, the precipitating pH of metalic sulfide or hydroxide is lower and the restrictive effects of the diffusion of the spin bath components into the alkali solution is larger. These results were discussed in relation to the spinning mechanism of viscose.

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The action mechanism of modifier in super high tenacity rayon spinning was studied. Combining the results of the previous studies on modifier with the present findings, it is shown that the action of modifier could be satisfactorily explained by the following mechanism.
(1) Amine reacts with NaOH and CS₂ in viscose and converts into Na-dithiocarbamate, which reacts with zinc ion in the spinning solution and precipitates as a more stable Zn-dithiocarbamate colloid than ZnS on ZnCS₃ colloid in a lower pH range.
(2) Polyethyleneglycol acts as a protective colloid of ZnS or ZnCS₃ colloid and stabilizes ZnS or ZnCS₃ in a lower pH range.
(3) When modified viscose is spun into the spinning solution, these more stable modifier-zinc chilate compound colloid than ZnS or ZnCS₃ colloid in a lower pH range initially, precipitates on the viscose filaments, forms a semipermeable membrane, and controls coagulation, dehydration and regeneration rate of the spinning fillament by the osmotic effects. Consequently, the fillament is dehydrated quickly, regenerated gradually at a lower degree of swelling and gives a cross section of all skin.

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In the previous report (A. TAKAOKA, J. Soc. Textile & Cellulose Inds. Japan, 18, 741 (1962)), the effects of heat-treatment of acrylic fiber on its dyeing properties had been investigated to determine if such heat-treatments prior to dyeing could be a major cause of variations in hue.
In this report, the effects of heat-treatment of acrylic fiber on its physical and chemical properties have been investigated to discuss the relation between dyeing properties and fiber structure. Samples of Orlon 42 were treated with hot water (100°-150°C), steam (100°-150°C), and hot air (100°-200°C) without tension, and then their physical properties (shrinkage, apparent fineness, specific gravity, tensile strength, breaking elongation, Young's modulus and whiteness) were measured. On the other hand chemical properties were examined by means of infrared spectrum analysis, elementary analysis (nitrogen content) and potentiometric titration (acid group content).
With regard to the effects of wet heat-treatment, the fibers shrank markedly, apparent fineness and wet breaking elongation increased, and tensile strength (g/d) and Young's modulus decreased. The higher the temperature of the heat-treatment is, the greater this tendency becomes. The effects of dry heat-treatment on the fiber properties are, by comparison, negligible. Specific gravity measured by means of the density gradient tube method increases a little both in wet heat-treatment and in dry one, but the increment is not so large as to discuss on the effects of heat-treatment conditions. High temperature treatment makes the fibers slightly yellow in both treatments, but no marked chemical change of the fibers is recognized from the results of infrared spectrum analysis and nitrogen analysis. It was however recognized that the acid group content decreases about 10% on hot water treatment at 140° and 150°C.
From these results, the change in dyeing properties on heat-treatment is reconfirmed to be due to the physical change of the fibers.

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The adsorption isotherms of Malachite Green (C. I. Basic Green 4) and Miketon Fast Red R (C. I. Disperse Red 17) on Orlon 42 acrylic fibers heat-treated with various conditions were determined at 100°C. The diffusion coefficient and activation energy of the basic dye were measured.
With regard to the effects of wet heat-treatment, the diffusion coefficient of the basic dye generally increases and activation energy of diffusion slightly decreases. The saturation value of the fibers for the basic dye decreases about 10% in the case of heat-treatment with hot water at 140°C and 150°C. The acid group content calculated from the adsorption isotherms is in accordance with that determined by potentiometric titration. This result means that the acid group would be in the amorphous region.
The partition coefficient [D]_F/[D]_S of the disperse dye generally increases on the heat-treatment. As the chemical change of the fibers on the heat-treatment has not been recognized, the most likely explanation for the increase in the partition coefficient of the disperse dye seems to be the change of the volume term of the fibers, and not due to the change of the affinity of the dye for the fibers.
With ragard to the effects of dry heat-treatment, the diffusion coefficient of the basic dye and the partition coefficient of the disperse dye slightly decreases. In the heat-tratment at 200°C, however, the diffusion coefficient increases, (activation energy decreases slightly, ) but the volume term of the fibers does not change.
The variation in the dyeing property as a result of wet heat-treatment may be explained by the conversion of quasicrystalline region into amorphous region.

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In order to study the photo-degradation of polypropylene (abbreviated as P. P.) films or fibers, the author has chlorinated by means of bleaching powder and sodium chlorite, the P. P. substances of which strength and elongation before and after the exposure to the carbon-arc of Fade-ometer have been estimated. The similar experiments on the chlorinated P. P., dyed with 3 different cationic dyes were also tried.
The results may be summarised as follows:
1) Chlorinated P. P. films.
A resistance to light of films is decreased to greater extent and after about 30 hrs' exposure they are completely destroyed. At the same time a remarkable decrease of elongation has been observed.
2) Films, dyed with cationic dyes after chlorination.
A resistance to light of the substance became inferior more rapidly as compared with those undyed, Thus the dyeing process seems to accelerate the photo-degradation.
3) Commercial P. P. fiber.
The similar results as 1) and 2) were observed. However in the degree of degradation there are no differences between the dyed and undyed fibers.

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Combination of morpholine ring into PVC molecules occured by heating or γ-ray radiation to PVC fiber in 70_??_90% aqueous morpholine.
The affinity to dyes of thus modified PVC fiber is improved by oxidizing these fibers in aqueous chlorine or hydrogen peroxide solution to form a dyeable functional group >C=O, -OH.
The forming of these functional groups seems to be induced by resonance of proton in PVC molecule due to the loan pair electron of nitrogen atom in morpholine ring combined with PVC.
Thus treated fiber has an increased affinity for many basic and suspension dyes.

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