Viscoelastic properties and proton magnetic resonance absorption of polyethylene terephthalate (“Terylene”) were observed in a temperature range from -70°C to 160°C. The viscoelastic behavior of Terylene agree well with the dielectric data obtained by W. Reddish, in which he reported two transition regions at about -40°C and 110°C. However, the interpretation of the low temperature transition process proposed by W. Reddish does not seem to be reasonable. From the theoritical analysis of the results of n.m.r and others, it may be concluded that the low temperature transition process corresponds to that of the rotational oscillation of methylene groups about their chain axis, accompanied by rotational oscillation of ester groups about the bond joining the ester group to the benzen ring.

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In the previous paper, the diffusion coefficients of plasticizers in the polyvinyl chloride compounds were reported, for the plasticizers, TCP, DOP and DOA, over the range of 20-140°C and 20-60 percent plasticizer. In this paper, the effects of plasticizer concentration and temperature were examined.Over 100°C, the diffusion coefficients were decided by the volume fraction of plasticizer, and there were little difference between plasticizers. At lower temperatures, the differences in plasticizer efficiencies appeared. Linearity could be found between logD and 1/T, where D is diffusion coefficient and T is absolute temperature, and activation energies increased rapidly as the plasticizer concentration decreased. By Eyring's theory on diffusion, the activation entropies were calculated.

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The spherulites made from the solution of commercial nylon 6 (Amylan No.1001A, made by Toyo Rayon Co.) were studied by the microscopes. At the first, by the polarization microscope, it was confirmed that the directions of molecular chains were always along the radii (Fig. 1 and 2). Secondarily, by the electron microscope, the directions of molecular bundles were discovered also to be radial (Fig. 3). And the boundary of spherulites were found to be feeble (Fig. 4). The shapes of nuclei looked like the sheaves (Fig. 5 and 6), as those of polyethyleneadipate.

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Theoretical composition of non-crystalline copolymers from methyl acrylate and methyl methacrylate was calculated from the monomer reactivity ratios using the Q-e values. The calculate dcomposition of methyl acrylate-methyl methacrylate copolymers is in good agree-ment with the composition given by the Gordon-Taylor's equation which is derived from glass-transition temperatures of binary copolymers, and the coefficients of expansion in the glassy and rubbery states. The composition of partially acetylated polyvinyl alcohol is also in good agreement to the composition given by the Gordon-Taylor's equation. The glassy transltion temperatures of copolymers were measured by electronic vibrating reed method.

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Viscosity of 10-20% aqueous solutions of PVA differs by the polymerization yield (higher than about 70%, or less than it), even if PVA samples have the same intrinsic viscosity. As the cause of this behavior molecular weight distribution or branching is supposed. To study which is the real cause, several samples were synthesized, which were different in the broadness of their molecular weight distribution and in the degree of branching, if PVA might have it, and the viscosities of these solutions were measured. From the results it was found that the viscosity is not affected by such a branch, but by molecular weight distribution. A parameter γ introduced to Baker's equation is about 4×10^-3 for unfractionated higher conversion sample, and less than 2×10^-3 for unfractionated lower conversion and fractionated higher conversion one.

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The moisture dependence of density was measured for diacetyl and triacetyl cellulose fibres and films by the flotation method using organic liquid mixtures as a medium. The density in water was also measured by a pycnometer. The density of the fibres has a maximum at a few percent regain, as in the case of most other fibres. The value of p, mass of sorbed water which has penetrated into the specimen of unit mass, was evaluated as a function of regain x. p is smaller for triacetyl cellulose fibre (acetic acid content 61.8%) than diacetyl cellulose fibre (a.a.c. 54%) through the whole range of x, presumably because of high crystallinity of the former. In the case of films, however, triacetyl cellulose (a. a. c. 60.5%) and diacetyl cellulose (a.a.c. 54.5%) show nearly the same p-x curve. This may probably be due to the fact that the both films are nearly identical in crystallinity degree, since they have undergone neither heat-treatment nor stretching. In all cases, p gradually increases with x up to the saturated value, which can be given from density in water.

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Propagation of ultrasonic waves in vulcanized and loaded natural rubbers has been investigated. Samples used are vulcanizates with 2-30 sulfur per 100 rubber and rubbers loaded with 20-60 carbon black per 100 rubber. Velocity and attenuation are measured at frequencies of 0.71-8.64Mc/s and in the range of temperature -60-100°C. All the samples show the attenuation peaks within the temperature range measured. These peaks shift to higher temperatures with increasing sulfur content but do little with carbon concentration. Activation heats obtained from the shifts of these peaks for different frequencies are 19-21kcal/mol for vulcanizates of 2-8PHR, 28kcal/mol for vulcanizate of 16PHR, and 20-22kcal/mol for loaded rubbers. The increase of effective modulus with loading, together with its temperature dependency is explained by the separate consideration of bulk modulus and shear modulus.

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In this report are described the results obtained from the experiments on the polymerization of AN in toluene solutions. 1) In the polymerization reaction, a small fraction of CN groups in the polymer molecule is liberated. 2) The radical life-time is in the order of magnitude of 10 mins. at 18.8°C. 3) When Dimethylformamide is added the expression of reaction rate at 30°C is Rate=K [BPO][AN] 2 which is the same as that expression previously obtained without DMA at 68°C. Consideration of these facts and the experimental results reported in the previous paper, gives the following mechanism. At lower temps. the reaction rate is affected by occlusion of the radical end, and the propagation process could be considered to consist of two stages, i.e. those before and after occlusion; the former contributing chiefly to the overall rate and the latter to the degree of polymerization. At higher temps. or in the presence of DMA, the effect of occlusion is not important; and so it is not necessary to assume two stages described above, but the reaction scheme to be considered is as follows:
Init. BPO+AN→R
Prop. R+AN→R
Trans. R+S→X+R
Term. R→X
(R: radical, X: inactive product, S: solvent)

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Polymerization reactions of styrene with Ziegler's catalyst system [TiCl₄-Al (C₂H₅) ₃] was studied in various conditions. Yields of isotactic polymer increase markedly with the concentration of the catalyst and decrease with the amount of solvent to that of monomer. Benzene can seperate atactic polymer in room temperature from isotactic polymer, and hot benzenemethanol solution serve as a crystallization medium for the polymer to crystallize.

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Average molecular weights of the cohydrolysis products of dimethyldichlorosilane and monophenyltrichlorosilane were determined by cryoscopic method in benzene solutions. Despite of their high viscosities, the measured values are of the order of 1000, and remarkably lower than that of silicone oils. Rast's camphor method was also applied to construct a simple method of determining molecular weight of commercially available silicone oils and varnishes. In spite of their disagreement of their physical characteristics, commercial varnish siloxanes have molecular weight ranging from about 1600 to 2200, and the difference between varnishes are relatively small. After the treatment for accelerating condensation, varnish siloxanes showed a distinct growth of molecular weight to the order of 2000, thus the number of silicon atoms in the single varnish siloxane molecule are evaluated to be about twenty.

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The polymerization of vinyl acetate in the presence of polyvinyl acetate (PVAc) contained double bonds on the backbone was examined at 60°C. The results obtained are as follows; 1) Degradative chain transfer occurs, and therefore the rate and degree of polymerization decrease. 2) From measuring the double bonds of the preoduced polymer, monomer transfer constant 3×10^-4 and k_r/k_p<10^-2 are obtained by kinetic analysis. Where k_r: activation rate constant of double bond on the backbone of PVAc, and k_p: propagation rate constant. From these results it has been shown that degradative chain transfer is predominant under this condition.

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By using azobisisobutyronitrile as initiator, the heterogeneous polymerizations of acrylonitrile in benzene or in benzene-dimethylformamide were carried out at 50°C. It was found that the initial rate of the heterogeneous polymerization, R_p, was expressed by the Eq.(5).
(5)
where [K] ₀ and [M] ₀ are initiator and monomer. Granting that termination step consists of two reactions which proceed spontaneously and bimolecularly, and that a definite fraction of the growing radicals terminates spontaneously, the Eq.(11) was derived.
(11)
Eq.(11) could explain the experimental results obtained. The values of A′ and B′ were computed.

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Cyclohexanediol (the cis-and trans-mixture) was prepared by the catalytic hydrogenation of hydroquinone. The separation of the cis-and trans-1, 4-cyclohexanediol (quinitol) from the mixture was accomplished by the method of Batzer, which consisted of converting the diols into the diacetates. The polymerizations to produce trans-quinitol polyester was carried out by heating trans-quinitol and adipylchloride (or sebacyl chloride) in nitrobenzol under nitrogen atmosphere. These polymers have good fibre-forming properties and the resulted fibres are capable of cold drawing.

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It was found, that the mobility of polyvinyl alcohol increases with the increasing ionic strength of the added salt. The phenomena may be explained by an equilibrium of adsorptive binding of the added salt by polyvinyl alcohol molecules. The tendency of the binding is almost independent from the conditions of the polymerisation of vinylacetate. The charge of the polyvinyl alcohol molecule without the adsorptive binding of the ions are obtained by the extrapolation of the value to zero concentration of the added salt. The extrapolated values are in good agreement with the values found by conductometric titration of the polyvinyl alcohols.

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Mol content (per monomer unit CH₂-CH (OH)) of COOH group in polyvinyl alcohol was determined by electroconductivity method. The content of COOH group per polymer was estimated from the mol content and the polymerization degree, determined by viscosity method. When the fractionation of polyvinyl alcohol was not done well, the apparent value of COOH content exceeded the theoretical value 1 far away and amounted to 2 or 3 in some case. When the fractionation was done well enough, it became about 1, as expected from the polymerization kinetics. The contents of COOH group of unfractionated samples derived from polyvinyl acetate polymerized in ester and in methanol are respectively 1 and less than 1. The COOH content of polyvinyl alcohol derived from polyvinyl acetate polymerized in succinic acid ester is 2 as expected, but in malonic acid ester is 1.

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Polymerization of vinyl acetate in the presence of butyraldehyde was studied by dilatometry at 60°C, using 2, 2′-azo-bis-isobutyronitrile as initiator. Polymerization rate is proportional to [AZN] 1/2 and k_t/k_p² value at constant concentrations of butyraldehyde is the same one with the case of bulk polymerization, 2.6. The determination of Carbonyl content in polyvinyl alcohol shows that one PVA molecule has nearly one Carbonyl group. These results indicate that butyraldehyde does not act as a retarder like crotonaldehyde but as a normal transfer agent like acetaldehyde. Its chain transfer constant is.

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