Undrawn Tetron polyester filament of low crystallinity was stretched by 6.6 fold and heat-treated at 205°C in an oil bath, where the filament shrank by 25%. The filament was further stretched at 100°C to the original length, and again heat-treated at 200°C allowing shrinkage. This stretching and shrinking cycles were repeated twice. The final length was 80% of the original length. The parameters of the fine structure are expressed: X(X-ray crystallinity)=0.346, f_x (X-ray orientation degree)=0.931, f₀ (over-all orientation degree)=0.571 and f_a (amorphous orientation degree)=0.664.
This stabilized filament was stretched toward the original length at 100°C and the fine structure was investigated at each stretching stage and the following results were obtained.
(1) The crystalline region is stable (X and f_x were kept unchanged during the stretching), while f₀ and f_a increase remarkably. The f_a_??_elongation ratio curve is convex to the draw axis saturating before it reaches the original length.
(2) The stretching degree of amorphous chains, r/nl, was estimated from the filament length.
The curve f_a_??_r/nl agrees well with the one calculated by the Treloar's rubber theory, where r is the end-to-end distance of the chain between net points, the crystallites nl the value of r at the fully stretched state, and_??_^-1 the inverse Langevin function. So the behavior of the amorphous chains within the polyester filament at 100°C or above may be considered to be nearly rubberlike.

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Polyvinyl alcohol film was cast from a 10% aqueous solution, which was swollen in a 50% ethanol solution and stretched 3 folds, followed by drying and heat-setting at 210°C for 2min. (I-film). It was contracted by 30% by heating at 226°C for 5 sec. in a free state and then dyed with_??_ Congo Red at 70°C (II-film).
II was stretched to the original length at room temperature in a moistened state and again contracted, the amount of contraction being controlled by changing the amount of regain and the temperature (not over 120°C). The dichroic orientation degree f_D, X-ray orientation degree f_x and the crystallinity X of the film were determined at each stage of the stretching and contraction. From these parameters the stretching degree of the amorphous chain v_a relative to the isotropic state, was calculated and plotted against the observed f_D.
As the results, it was found that f_D changes with v_a nearly reversively by the stretching and the contraction, and the amorphous part deformes according to the Kratky's first deformation mechanism under the experimented conditions.

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The variation of creep and creep recovery with temperature and the ultimate tensile properties under constant load were studied for acrylonitrile-methylacrylate copolymeric fibers containing different amounts of methylacrylate (MA), and the effects of the copolymer composition on the ultimate tensile properties are discussed. The composite curves of the tensile strength against the time to break plotted double logarithmically exhibit an identical shape being independent of the copolymer composition, so that a critical condition for rupture may be assumed as equivalent. The temperature dependency of the shift factor along the logarithmic axis of the time to break and the values of a characteristic temperature are identical among samples, at least practically. Therefore, it is assumed that the composition of amorphous phase is essentially equivalent within the region of the MA fraction (6_??_12wt. %) used. The “failure envelope” over the transition zone and the rubbery and/or leathery zone changes to a more sharply convexed shape with increasing the MA fraction. On the other hand, it is obtained from the experiments of the creep and creep recovery that the response against external force becomes more sensitive with increasing the MA fraction. The variation of the “failure envelope” with the copolymer composition may be explained by a constancy of critical condition and the variation of the response against external force.

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Relatively simple apparatus for the measurement of radiation coefficient of solid high polymer at room temperatures (10_??_55°C) was devised. Difficult problems such as calibration of detector by standard tungsten lamp and calculation of view factors between sample and detector, were considered. Calibration was made by specially prepared standard plate and the accuracy was checked by the use of samples which have known values of radiation coefficient.

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Radiation coefficients of textile fabrics and films are considered to be important in relation to their practical usages. These materials were subjected to the measurement on the apparatus previously reported. The radiation coefficient of cotton fabrics at room temperatures was 4.4 (kcal/m²•hr•°W⁴), a comparatively large value. In the measurement of apparent radiation coefficient of films of polypropylene and polyethylene terephthalate, it was found that the considerable thickness of the samples was neccessary to reach a certain radiation coefficient owing to the small absorption coefficient α (1/m) of the films. This kind of radiation is profoundly different from the surface radiation which is frequently encountered in ordinary substances.

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It is a matter of importance to discuss the elastic behavior of the warp yarn subjected to transverse impact caused by the heald during the weaving.
In the present, a description is given of the equipment built to measure the propagation time of tension in the yarn by the transverse impact loading.
The following results were obtained:
(1) The propagation time of tension ranging approximately from 70 milli-sec/m to 100 milli-sec/m was observed with this experimental apparatus. The propagation velocity of tension was effected by the guide roller R. (See Fig. 1) (It may be substituted by the speed of propagation _??_anging approximately from 10m/s to 14.29 m/s.)
(2) In general, the propagation time of tension in the yarn increases with decreasing Young' modulus of the yarn.
(3) This propagation time of tension in the yarn seemed to be markedly depedent upon the material of fibers in the yarn, and not dependent upon the count of yarn.

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Reaction mechanisms of photodegradation of cellulose have been proposed under consideration of the experimental facts obtained in report (1) to (VI). The degradation mechanisms are different according to wavelength of light used in irradiation experiments, i.e., (1) on irradiation by λ 1850A, the photochemically primary dissociation occurs in cellulose by its strong absorption of light of this wavelength, the reaction being independent of the presence of oxygen. At the comparatively early period of exposure, direct scission of glucosidic linkage predominates but on prolonged exposure, the formation of 2, 3- dialdehyde by splitting off H-atoms from secondary carbon atoms of the molecule occurs, the latter being easily degradated by alkali medium such as cuam solution. (2) On the other hand, coexistence of oxygen is indispensable to the photodegradation by λ 2537 A irradiation. In this case, absorption matter of λ 2537A is oxygen molecule (Herzberg band), because cellulose is transparent against visible and ultraviolet light having a wavelength longer than λ 2000 A. The main initial step of this reaction is as follows: the excited oxygen molecule thus formed abstracts a hydrogen atom from 1-carbon atom of pyranose ring to form cellulose radical and this reacts with oxygen and other cellulose molecule to produce cellulose peroxide as can be seen in the case of autoxidation of ordinary hydrocarbons. This peroxide is then decomposed photochemically and at the same time, the chain is broken into two chain fragments, accompanying the formation of δ-lactone as the end group of one fragment. The end group of the other fragment has the same configuration as ordinary cellulose molecule. The lactone end group is further hydrolyzed photochemically under the trace of water to form hydroxy-carboxilic acid end group.
The quantum yields of each wavelength are calculated and the following values are obtained: γ (1850A)=1×10^-2, γ(2537A)=0.5×10^-2. Both values are far smaller than unity. The cause of these small values may be attributed mainly to the cristalinity of cellulose fine structure, i.e., in the case of λ 1850A irradiation, recombination of two dissociated chain fragments occurs in crystal region according to Franck-Rabinowitch theory, while in the case of λ 2537A irradiation, diffusion of oxygen molecule, necessary for photoxidation, into this region are difficult and in consequence, photoxidative degradation is inhibited. In both cases, role of crystal region reduces the quantum yield.

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The graft copolymerization of acrylnitrile onto wool fibers by H₂O₂_??_NaHSO₃ redox method was studied with the following results.
1) The reaction rate of the graft copolymerization of AN. is expressed by the following equation as the MMA.¹⁾
Where, θ…the degree of grafting for total AN. used.
k…the reaction rate constant of grafting.
t…the reaction time.
The apparent activation energy of AN. graft copolymerization calculated from the relation between l_nK and 1/T by A rhenius equation. is 21.7 Kcal/mol. and the reaction rate constant K depends on the reduction catalytic concentration, but there is little effect on the reaction rate in the case of the concentration above 5% NaHSO₃.
2) According to the IR. spectroscopic study, the characteristic absorption band can be found on the wave number 1020cm^-1, presumably identified to the stretching vibration of the ether linkage. But, the grafting point of the wool which leads to graft copolymerization can not be thought of as the OH groups present in the keratin molecul from this result.
3) The molecular weight of the grafted polyacrylnitrile is above the order of 10⁵; the tensile strength and Young's modulus, increase with the rising degree of grafting, but the elongation decrease.
4) The effects of the heat-setting on the AN. grafted wool are improved with increasing the degree of grafting.
Note. 1) J. Soc. Fiber Sci. and Tech., 22, Feb. (1966)

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Throughout the study of chemical behavior of high polymers in liquid sulfur dioxide, it has been found that natural cellulose is soluble in liquid sulfur dioxide with addition of amines. Amines which exert a dissolving effect upon the cellulose are secondary or tertiary alkyl amines, such as diethylamine and triethylamine. In present work, diethylamine was employed as dissolving agent. The cellulose fiber such as ramie (_??_p 2, 000), linter pulp (_??_p 670) and commercial grade dissolving pulp can be dissolved rapidly at ordinary temperature in sealed reaction vessel.
It is an interesting fact that there is stoichiometric relation between the amount of dissolved cellulose and amine used. The cellulose fiber can be dissolved completely with addition of 3moles of amine for each glucose unit without any decomposition or depolymerization of cellulose molecule. In other words, an equivalent amount of amine for each free hydroxyl group is enough to dissolve the cellulose completely.
The obtained dope consists of cellulose-amine-SO₂ and it is colored orange yellow and quite clear viscous solution. Left standing for a few days in sealed tube, no change in the above solution has been found.
Cellulose disolved in liquid sulfur dioxide is easily regenerated by treatment of water or alcohols into the form of filament or film. When the solution is allowed to stand in atmosphere, sulfur dioxide gas is evaporated rapidly leaving the mixture of cellulose and amine-SO₂ adduct.
The cellulose is regenerated perfectly from the mixture by further treatment with water or alcohols.
The mechanism of the above phenomena has not been confirmed. But a hypothesis may be assumed from following standpoints.
It has been mentioned already that the dope consisted of cellulose-amine-SO₂ is remarkably unstable in neutral solvents such as water or alcohols and even in atmosphere. Therefore, there is no evidence of formation of stable complex molecule between cellulose and amine or sulfur dioxide.
Meanwhile, according to literatures, the characteristics of reactions in such solvent has been pointed out by many workers. From many aspects of experimental behavior such as the ability to change the color of indicator or conductivity relationships or the change of color of amine-SO₂ adduct from yellow to colorless with addition of acids, these workers have emphasized the acidbase reaction theory in such solvent system.
The color of amine-SO₂ adducts disappeares with addition of excess cellulose.
From these standpoints, the reaction scheme may be assumed as follow.
R₃N+SO₂→R₃N•SO₂ (yellow)
R₃N•SO₂+Cell-OH→R₃NH⁺+Cell-O^-+SO₂ (colorless)
Furthermore, the molecule of sulfur dioxide may be shown as a resonance hybrid of following structures.
It is not surprising that sulfur dioxide act as a splitter on cellulose fiber. The sulfur dioxide molecule may be absorbed strongly to the ionized macro-molecule of cellulose. The macro-structure of cellulose fiber may be degraded by “splitting effect” of sulfur dioxide and the splitted cellulose molecule disperses then in the solution.
The formation of complex of cellulose, amine and sulfur dioxide has not yet been confirmed.

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