Molten polyethyleneadipate was spreaded on the slide-glass and cooled gradually at 27°C. And the growing process of the spherulite was observed under the polarization microscope between crossed nicols. At the first, small straight molecular bundles imerzed here and there. And they grow in three ways respectively, -i. e., (1) Some of them grow, but stay straight.(2) Some of them grow with the both ends spreading out.(3) The remainder of them grow with the ends spreading out until the outlines of them unite together. Then new radiating rientation occur around each type of these molecular bundles, and form spherulites. Acordingly these molecular bundles should be called the nuclei of spherulites. The types of nuclei are not essential. They seem only to owe to the surrounding temperature and the ension caused by original nuclei or small straight molecular bundles. The large spherulites a half inch in diameter were obtained by extremely gradual cooling from the melt. Someimes cracking occurred in the spherulites. The directions of the cracks were along to the radii, but exceptionally to the circle.

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In the case of measuring dielectric constant and loss factor of fiber itself, there are such difficulties as the anisotropy of fiber, the great influence of water sorption, and the fact that they can be measured only in the condition of the existence of the air or the other medium; therefore, in this report, the authors explain about the apparatus and the operation for measuring the dielectric properties of fiber itself, perfectly controlling these factors. In the measurement of moistened samples at low frequency region (50 c/s-20 kc/s), the effect of conduction current being great, the results of the measurement can not be analysed by Cole-Cole's circular arc law, which is applicable to dipole polarization.In such a case, by the method of plotting complex resistivity instead of complex dielectric constant, a circular arc corresponding to Cole-Cole's is obtained and the frequency characteristic can be represented by a few constants.

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The rate of the emulsion polymerization of acrylonitrile, where polymerization was initiated by APS and emulsion was stabilized by PVA., was approximately given by:_??_The mean degree of polymerization of polymer is higher, with (1) higher monomer concentration, (2) lower temperature of polymerization, and (3) smaller amount of the initiator. Considering various facts, such as proportionality of rate of polymerization to [I₀], initial decrease of the mean degree of polymerization with the increase of PVA concentration and the rate and activation energy of initiation, chain transfer of acrylonitrile with PVA must not be neglected.

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The inhibition period of acrylonitrile polymerization initiated by K₂S₂O₈ in acqueous medium, was investigated by means of dilatometer in various monomer-, initiator-, and inhibitorconcentrations under various temperatures. It was found that the inhibition period was proportional to the inhibitor-concentration and to the reciprocals of both the monomer- and the initiator-concentrations, and their relations were determined in details under various temperatures.

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The equation which gives an account of the relations reported in the previous paper was obtained according to the theoretical consideration in regard to kinetics of the inhibition, and Mark-Hohenstiens idea concerning the calculation method of the activation energy of initiation reaction was discussed in details.

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Styrene liquid or vapor easily polymerizes to very high polymer on the surface of metallic sodium. The polymerization velocity is measured by the method of dilatometer. Inhibitors, such as hydroquinone or cathechole, do not inhibit or retard the polymerization, and therefore this is not a radical polymerization.

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Metallic sodium reacts with styrene monomer and makes an addition compound. This compound is red-brown or red-violet and very reactive. This addition compound initiates the polymerization. The structure of this compound is decided by the masspectrometry of the resultant from the decomposition with water vapor.

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Polyvinyl alcohol (PVA) with an average DP of1000was fractionated, five fractions (DP1620, 1430, 890, 790 and 340) were selected for the experiment and acetylated to obtain three series of samples of different degree of acetylation (22, 25 and 32mol%). Aqueous solutions of the partially acetylated PVA were prepared and the relation between the temperature of phase separation and the concentration of the solution was experimentally established. It was observed in all these cases that the solution had a critical temperature under which phase separation did not occur. The experimentally found critical concentration was somewhat higher than the calculated one according to the Flory's theory. It was attributed to the dependency of thermodynamic constants on the concentration of the solution. Thermodynamic constants were calculated from the relation between the critical temperature and the molecular weight of the polymer.

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It is well known that, the addition of reducing agent which can be oxidized by persulphate results in a very much enhanced rate of polymerization (A), (A) S₂O₃^--+S₂O₃→SO₄^-+SO₄^-·+S₂O₃^-·
We found that, the reduction and oxidation reaction obtained by salts of oxy-acids of salphur with reducing properties (Na₂SO₃, NaHSO₃, Na₂S₂0₃, Na₂S₂0₄ and SO₂) and ferric salts (or cupuric salts), is responsible for the initiation act (B), (C).(B) S₂O₃^--+Fe⁺⁺⁺→S₂O₃-·Fe⁺⁺ (C) HSO₃^--+Fe⁺⁺⁺→HSO₃+Fe⁺⁺ and the effect of temperature, monomer concentration and catalyser concentration were studied.

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The thermal degradation of polymethylmethacrylate was proceeded only by end initiation (k₁, rate constant) under 300°C, but in accompany with random initiation (k₁, rate constant) above that. The initial rate of volatilization was derived from the statistical consideration of chain mechanism and applied to our experimental results. Activation energy for k₂ and probability of depropagation were computed as 51 kcal/mol and 0.9994. Comparing the degradation of polymethylmethacrylate to that of polystyrene following to the same initiation, the former is rather small in k₂, but very much larger in the kinetic chain length than the latter.These can be understood on the basis of their molecular structure.

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Studied on the thermal degradation of styrene-methylmethacrylate copolymers of various compositions. In the one of smaller styrene molar fraction m₁ in copolymers, the velocity of monomer generation decreased severely with increasing m₁, in the other of larger m₁ only little. Molar ratio of volatiled monomers computed by analysis of carbon content of the degraded copolymers was constant through all degradation processes and so is a priori determined by initial copolymers. Assuming random initiation, the statistical equation in Part III was applied to our experimental results. Average rate constants for initiation changed almost linearly with m₁, but average kinetic chain lengths decreased largely in smaller m₁.

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