Relationships between limiting viscosity number and molecular weight of poly-(vinyl alcohol)(PVA) were studied. It was confirmed by light scattering method that the molecular weight of reacetylated PVAc agreed well with that of the original PVAc specimen, when the PVAc was obtained in low conversion (<10%). Therefore the degree of polymerization of the original PVAc was used for that of the corresponding PVA. The viscosity of aqueous solution of PVA depends on the rate of shear in the range 0-1000 sec-^-1 at 30°C, when the degree of polymerization of PVA exceeds 1700, and so in such a case the viscosity were corrected to that of zero rate of shear. The relationships between the corrected limiting viscosity number in ml/g [η] and weight and number average molecular weights M_w and M_n for the low coversion of PVA were given by:[η] =4.28×10^-2M_w^0.64 and [η] =6.70×10^-2M_n^0.64. The latter equation is coincident with Nakajima's equation obtained in a series of crude fraction of PVA. From these equations for the low conversion samples, the following relationships were derived for the perfectly homogeneous fraction:
[η] = 4.53×10^-2M^0.64 and [η] = 5.08×10^-1P^0.64
were P is the degree of polymerization.

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Vinyl monomers can be grafted onto conventional fibers by ionizing radiations. When nylon and cellulose are used as trunk polymers, it is necessary and usefull to mix the vinyl monomer with water and/or methanol. Young's modulus and rigidity of the graft copolymer increase when the vinyl polymer to be grafted has a high transition temperature such as styrene, methyl methacrylate, and acrylnitrile, and decrease when the vinyl polymer has a low transition temperature such as methyl acrylate and ethyl acrylate. Other properties of graft copolymer such as breaking strength and moisture regain are also studied.

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The molecular weight-intrinsic viscosity relation for poly-(trifluorochloroethylene) was determined. The solution viscosities of three samples in 2, 5-dichlorobenzotrifluoride (solvent 1) and in o-chlorobenzotrifluoride (solvent 2) were measured at 130°C with the viscometers of Ubbelohde type and modified Fitz Simons type. By using the Walsh and Kaufman's equation for solvent 1, the molecular weight-intrinsic viscosity relation for solvent 2 was given by

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The stress distributions of filament in bent yarn have never been seen experimentally. So the stress distributions in the cross section and the longitudinal direction of bent undrawn Tetron filaments are studied photoelastically in this paper. As the results, it is known that when the curvature is small, the compressible stress is equal to the tensile stress and when it is large, the compressible one is larger than the tensile one and the stress distributions in the longitudinal direction of bent filaments differ according to the textile kinds and the radius of carvature.

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As the yarns in textile fabrics are made of many twisted filaments or fibers, the stress distribution in the cross section of bent and twisted filaments is studied photoelastically in this paper. As the results, it is proved experimentally that the stress in the bent and twisted filaments is smaller than the bending stress in the simple bending.

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The results of light scattering measurements on the same sample in Japan are reported. Although our technique involves several points to be improved, it may be said that a satisfactory accuracy has been obtained.

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The crystallinity of polyethyleneterephthalate was successively changed by the thermal treatment of the amorphous film at 120, 150, 210 and 238°C. The effect of crystallinity on the glass transition temperature, T_g, and on the volume expansion coefficient, α, of the sample were determined from volume measurements over the temperature range 25°C to 98°C. For the low-temperature-crystallized sample T_g shifts rapidly to higher temperatures. The expansion coefficients of the high-temperature-crystallized sample falls linearly from the valueof the amorphous sample with increasing crystallinity, while that of the low-temperaturecrystallized sample falls rapidly at the initial stage and then, describes a curve parallel to the former. These may be related quantitatively to crystallinity and size of crystallites, assuming that crystallites act as physical crosslinks.

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Intrinsic viscosities of polyvinyl benzoate fractions of DP=1620-660 were measured in a critical consolute solvent (xylene at 32.5°c).(r₀²/r₀f²) ^1/2 and M₀ [η]θ/P^1/2, each of which, according to Flory's theory, provides a measure of extension of polymer coil in θ solvent were calculated from the experimental results. These values were 2.65 and 1.14 respectively for this polymer, and were larger than the corresponding values reported for other vinyl and vinylidene polymers. This may be attributable to the effect of bulky and rigid side chains of polyvinyl benzoate.

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In the previous paper we have reported that (1) the four bands (A), 1364, 1314, 1297 and 1185 cm^-1, in the infrared spectra of isotactic polystyrene (IPS) and its derivatives might be closely associated with the helical structure of these isotactic polymers and the 983 cm^-1 band (B) of IPS exhibits remarkable increase of the intensity with crystallization. Furthermore, we have inferred from the experimental results obtained so far that the bands (A) are originated from the intramolecular interactions in the helix of the molecular chain, and the band (B) from the intermolecular interactions between the neighboring chains in the crystalline region. In this paper, the investigation carried out for the purpose of confirming these inference is reported. The infrared spectrum of the film of the mixture of IPS and poly-α, β, β-trideuterostyrene (IPTDS)(2: 8 mole fraction) was measured, and it was found that the bands (A) are subjected to no effect in spite of the fact that IPS molecule is believed to be surrounded statistically by IPTDS molecules. On the other hand it was found that in the case of the mixture of IPS and poly-p-deuterostyrene, the band (B) is obviously decreased in its intensity. Those experimental facts may indicate the adequateness of the inference mentioned above.

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α-Methylstyrene was polymerized by BF₃·O (C₂H₅) ₂ in various solvents at -20, -50 and-70°C in order to obtain some relations between the nature of growing ion pairs and elementary reactions in cationic polymerization. Reaction rate constants were calculated from the degrees of polymerization of poly-α-methylstyrene and were plotted against the dielectric constants of polymerizing solvents. Monomer transfer reaction constant (k_tm/k_p) was found to be of the lowest value when the dielectric constants were in the range from 5 to 7, and this tendency did not change by varying the polymerization temperature. Spontaneous termination reaction constant (k_t′/k_p) increased strongly by increasing dielectric constants of solvents above 6, but k_t′/k_p had a small constant value below 6. This relation also did not change by varing the polymerization temperature. Considering these reaction rate constants, the solvent effect in the polymerization of α-methylstyrene reported previously could be explained. And also it could be understood that the nature of growing ion pairs was strongly affected by the kind of solvents.

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Velocity and attenuation of both transverse and longitudinal waves in high polymers were measured at the frequency of 2.25Mc/sec in the temperature range from 20°C to 190°C. It is found that temperature dependence of the real part of the shear modulus G₁ in polystyrene and polymethyl methacrylate is slightly different from that of the bulk modulus K₁. The imaginary part of the shear modulus G₂ is somewhat smaller than that of the bulk modulus K₂ and the temperature at the peak in G₂ is about 10-15°C lower than that in K₂. Temperature dependence of G₁ and K₁ in polyvinyl chloride is about the same. Moreover the temperatures giving the peak values for K₂ and G₂ are almost the same.

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As to the determination of properties of these products as surfactants, simillar methods mentioned in II. report were employed. So for as the size of molecular weight was concerned, it was found that smaller the size the greater the activity. In general the properties seem to be superior than those of the products mentioned in II. report.

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Vinyl n-butyl, i-propyl and ethyl ethers were polymerized by BF₃·O (C₂H₅) ₂ at -78°C in order to compare with the polymerization of vinyl isobutyl ether. It was found that the stereoregurality of the obtained polymers could be estimated by the precipitation temperature or Young's modulus as well as X-ray diffraction patterns, and the polymers of more isotactic structure were obtained at low monomer concentration. But from these monomers we could not obtain polymers having a high stereoregularity such as those obtained from vinyl methyl and isobutyl ethers. It could not be clarified whether this cause arise from the difference of the degree of isotacticity or crystallinity of the obtained polymers.

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Possibility of low temperature polymerization of styrene by Friedel-Crafts catalysts has been examined. In methylene chloride solutions with monomer concentration above 10vol%, a polymer of fairly high molecular weight was obtained in high yield by SnCl₄ or TiCl₄ catalyst. Addition of non-polar solvents such as n-hexane or chloroform decreased rate and degree of polymerization. Polystyrene obtained at -78°C in methylene chloride-SnCl₄ system dissolves almost completely in chlorobenzene at room temperature, but is partially insoluble in methyl ethyl ketone. This insoluble part is not recognized when trichloroacetic acid is used as cocatalyst or TiCl₄ is used as catalyst, and is found to increase when appropriate amount of n-hexane is added into methylene chloride. The difference in solubility might be due to the difference in stereospecificity, but could not been identified by X-ray diffraction patterns for the polymers obtained.

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Water-swollen poly (vinylalcohol)(PVA) films were irradiated at room temperature in air with γ-rays up to the does of 1.2×10⁷r. The degree of swelling was 2.5-3. No gel formation was observed and the scission of the main chain predominated. The G-value for the scisson was 6.7. It was found that the carbonyl and carboxyl groups were formed by the scission and that these groups increase with increasing dose. When irradiated to the dose 1.2×10⁷γ, the ratio, carbonyl groups to carboxyl groups formed was 2:1. The total of these groups were 60-90% of the total end groups formed by the scission. Oxygen in air and water play important roles for these radiation effects.

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Some properties of concentrated aqueous solutions of mixtures of polyvinyl alcohol (PVA) and polyacrylic acid (PA) were studied for the purpose of preparation of synthetic fibres from them. PVA solution and pure PA solution were miscible in all proportions, but when NaOH was added they became immiscible except in limited proportions. The viscosities of mixtures of PVA and PA solutions increased with time more rapidly than that of PVA or PA solutions. In the presence of HCl and at elevated temperatures, the gelating of the solutions occured in a few hours which was followed by syneresis. The gels thus obtained were insoluble in water even at 160°C under a high pressure, but were partially soluble in hot aqueous solutions of NaOH. The gelation and syneresis of the solutions may be attributable to the intermolecular ester linkage between hydroxyl groups in PVA and carboxyl groups in PA.

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The composition distribution, both intermolecularly and intramolecularly, of partially saponified polyvinyl acetate (acetyl content 20-30mol%), which had been prepared under various conditions with sodium hydroxide in the system of methanol and water mixture, was investigated by the temperature-turbidity relations or sodium chloride concentration-turbidity relations for the aqueous solutions.(1) If the mixing of the polyvinyl acetate solution and the sodium hydroxide solution is uncomplete, the prepared samples are heterogeneous in relation to the intermolecular composition.(2) The concentration of the polyvinyl acetate solution has no effect, up to 30%, on the composition distribution of partially saponified polyvinyl acetate.(3) With increase of the saponification temperature and decrease of the water content in methanol in the system of the saponification, the heterogeneity of the composition of the prepared samples increases both intermolecularly and intramolecularly.(4) The facts mentioned above, suggest that the acceleration to the rate of the saponification is more violent in the conditions of the higher saponification temperature and the lower water content.

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