For the design of solid-conveying section of plastics machinery it is necessary to know the characteristics of powdery and granular solid plastics. In this study, compression characteristics, internal and external friction of some kinds of solid plastics are measured. The compression characteristics are found to vary extremely with temperature. The angle of internal friction is obtained from Coulomb's law. It is also found that the coefficient of external friction between metal surface and solid plastics is fairly influenced both by pressure and by flatness of metal surface.

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From the studies on meltviscosities of poly-(chlorotrifluoroethylene) the following relationship was obtained:
logη=-18.70+3.5logM+15.1×10³/2.3RT
where η was the melt viscosity determined by parallel plate plastometer, M the molecular weight from the intrinsic viscosity of o-chlorobenzotrifluoride solution, R gas constant, and T absolute temperature. The experiment was carried out in the molecular weight range, 1×10⁵-5×10⁵ and in the temperature range, 500-556°K.

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Viscosities of dilute solution of polyacrylonitrile were measured in dimethylsulfoxide, dimethylformamide and 60% aqueous solution of ZnCl₂. Dimethylsulfoxide and dimethylformamide solutions were stable against heating at 90°C, whereas a comparatively large viscosity drop was observed with ZnCl₂ solution. Concentration dependence of dilute solution viscosities of the dimethylsulfoxide solutions is given by the following relationship
Viscosities were measured at 20-60°C. In this temperature range, the magnitudes of intrinsic viscosities of these solutions were in the following order: ZnCl₂ solution>dimethylsulfoxide>dimethylformamide. Intrinsic viscosities of polyacrylonitrile solutions were measured in binary mixtures containing dimethylsulfoxide and a nonsolvent as a function of temperature and the composition of the mixture. Actone, acetonitrile and water were used as the nonsolvents. The results were discussed in terms of the molecular structure of the solvents.

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The solvent power of dimethylsulfoxide was compared with that of dimethylformamide for the following polymers: polyacrylonitrile, acrylonitrile-methylacrylate copolymers, polyvinylalcohol, polyvinylchloride, polyvinylacetate, polymethylacrylate and polystyrene. Solubility of the heat-treated films, intrinsic viscosity and the “dilution ratio”of the solutions were used as a measure of the solvent power. It was found that dimethylsulfoxide is better solvent than dimethylformamide for the polymers having great cohesive energy density, such as polyvinylalcohol and polyacrylonitrile.

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In the previous reports, it has been shown that the degree of crystallinity of nylon 6 is increased by heat treatments and that the diffusion rate of dyes is increased by steam-setting, while it is decreased by dry-heat-setting. These phenomena have been explained in terms of the packing structure of amorphous parts of heat-treated polymers. In this report, the results supporting this explanation are obtained from a quantitative analysis of infrared spectra. Heat-treated nylon 6 films (their thickness are 10-20μ) were reacted with D₂0 at 60°C for 100 hrs. in vapour phase. Integral intensities of N-D stretching vibration band on the spectra were calculated as follows.
1/(1-α) l·∫logI₀/Idr=K′·C
where l₀ and I are the intensity of the incident and transmitted light respectively, l, the thickness, and a, the degree of crystallinity. Here, K′·C represents the number of unbonded N-H groups in the amorphous part. The result shows that K′·C increase by steam-setting while it decreses by dry-heat-setting. Thus the said structural changes in the amorphous part. are recognized.

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Some bi-functional compounds containing one or two pyrrolidone rings were synthesized by the reaction of itaconic acid with ethylenediamine, hexamethylenediamine, and N-carbethoxyhexamethylenediamine etc., in water or basic solvent such as pyridine. By the polycondensation reaction between these compounds and aliphatic diamines, the polymers having amide or amide-urea groups were prepared. They have shown fiber-forming property, but are not suitable for textiles owing to their water-soluble property. Compared with polyvinyl-pyrrolidone (Albigen A), these polymers showed somewhat lower stripping power.

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Dry poly (vinylalcohol)(PVA) powder was irradiated at room temperature in air with Trays up to 9.0×10⁷r. The scission of the main chain predominates, although chain branching reactions might also occur. The G-value for the scission was 0.9. It was found that equal amount of the carbonyl and carboxyl groups were formed by the scission and increased with increasing dose. It appears that the γ-irradiation gives rise to one carbonyl group and one carboxyl group per a molecule. Oxygen in air plays a significant role for these radiation effects.

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Dry poly (vinylalcohol) powder was irradiated in vacuo at room temperature with γ-rays up to 1.1×10⁸r. The scission of the main chain predominats as in the case of the irradiation in air. The G-value for the scission was 1.0. It was found that also in this case the carboxyl and carbonyl groups were formed by the scission. The amount of these groups formed was much smaller than in the case of the irradiation in air. The number of the two groups was equally 0.3-0.4 per a degradated molecule.

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The chemical change of PVA caused by H₂O₂ in neutral aqueous solution at 60°C has been studied. In the reaction, PVA is degradated remarkably and shows characteristic ultraviolet absorption spectra, especially at 270 mμ and increases the content of carbonyl group which are resulted from the scission of PVA chain and the oxidation of the main chain. Furthermore, the carbonyl groups situated in the main chain may be partially in the β-diketone structure facilitates the scission of the chain during the reaction. The formation of carboxyl group proceeds rather slightly compared with that of carbonyl group under the conditions studied.

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In order to obtain high polymers by reacting bisepoxy compounds with bifunctional nucleophilic reagents, the addition reactions of 2, 2-bis [p-(1, 2-epoxypropoxy)-phenyl] propane (I) and 1, 4-bis (1, 2-epoxypropoxy) benzene (II) with monoamines, diamines, dimercaptans, dicarboxylic acids and diols were investigated. The polyaddition reaction of bisepoxy compounds with primary monoamines and secondary diamines, resulted to linear polymers, which were soluble in organic solvents. While all the reaction products with primary diamines were insoluble and infusible, probably due to cross-linking. The reactions of (I) or (II) with dimercaptans, dicarboxylic acids and diols, also gave insoluble and infusible polymers, and their reaction velocities were slower than the amines. From these facts, it is considered that primary monoamines act as bifunctional compounds and primary diamines at tetra functional, and in case of the reaction of dimercaptans, dicarboxylic acids and diols, the secondary hydroxy groups formed by opening the epoxy ring are attacked by another epoxy groups, leading to formation of three dimensional net-works.

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