In order to investigate the crosslinking reaction in the oxidation of rubber, some experiments were carried out. Various methods for the intermittent stress relaxation measurements, the mechanism of crosslinking and the relationship between the quantity of crosslinks and the elongation ratio in the oxidation, were discussed, and the following conclusions were obtained.
1) The newly formed crosslinks which were determined by the intermittent stress relaxation method did not give good coincidence with the results obtained by other measurement methods.
2) The extent of crosslinking reaction was independent of the elongation ratio (1.0-2.5) in the oxidation.
3) The network structure of the rubber oxidized in the elongated state was the same as that in the original sample, from the view point of motion of polymer chains.

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The change in crystalline state with temperature for a well-annealed specimen of nylon 6 has been investigated by means of X-ray diffraction method. The sample used is in this study is unoriented film which was prepared by casting from formic acid solution. The film was annealed sufficiently so as to obtain the crystalline state having a high degree of order. The measurements of X-ray diffraction were made at various temperatures between 20°C and 260°C., using an X-ray diffractometer equipped with sample-heating unit. As the temperature is raised, the two principal spacings, (200) and (002), (202), of the α-form cell seem to converge toward a value, but do not arrive at the final coincidence below the melting point (220°C). On the basis of the diffraction curve at each temperature, the degree of crystallinity was determined according to the procedure developed by Krimm and Tobolsky. The relation between the crystallinity and temperature shows that melting of the sample appears first at about 180°C, which is further followed by the fusion of major crystalline part within a narrow temperature range from 200°C and 220°C. Finally the scattering curves for polymer melts were examined and it was suggested that a kind of ordered state of the hexagonal packing of molecular chains may exist in the melt at temperatures not far from the melting point.

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There is no precise determination made so far on the melting point of polyvinylalcohol (PVA). In the present paper, the melting points of the mixtures of PVA with ethylene glycol were measured at various concentrations, and the melting point of pure PVA was evaluated by extrapolating the melting points obtained above to v₁=0. As a result, the melting point of commercial PVA was 267°C, that of isotactic PVA 212°C, and that of syndiotactic PVA 267°C, respectively. Then by using Flory's melting point depression formula, the interaction parameters of commercial PVA with water, ethylene glycol, DMF and acetamide were estimated. The result was that the interaction parameter of PVA with water nearly agreed with that obtained from osmotic pressure measurement.

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Molecular weight and molecular weight distribution of linear polybutadiene (cis-1, 4 35%, trans-1, 4 55%, 1, 2-vinyl 10%) polymerized with Li catalyst were studied by gel permeation chromatography. Prior to our research, relationship among solute concentration, elution velocity, injection time, column combination, and elution peak were found.
By decreasing concentration or increasing elution velocity or shortening injection time, count of elution peak was shifted to lower count. Calibration curve of gel permeation chromatography, intrinsic viscosity and weight average molecular weight (by light scattering) were determined using fractionated samples. M_w by gel permeation chromatography method was in good agreement with M_η by viscosity method using another series of the fractionated samples.

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The following kinetic equation is obtained for the polyesterification of 2, 2-dimethyl-1, 3-propanediol with various dibasic acids at different temperatures in the absence of a foreign acid and solvent.
These reactions were found to be subject to general acid catalysis in the absence of a foreign acid and solvent, where a catalyst is the dibasic acid itself.
All of data obtained in this paper support the setting of the above equation over the range of 0 to 95% polyesterification for the case of [OH] ₀/[COOH] ₀=1.05, where [OH] ₀ is the initial concentration of the hydroxyl group, [COOH] ₀ is the initial concentration of the carboxyl group, and k′=4.8×10^-2.
The order of reactivities of dibasic acids with 2, 2-dimethyl-1, 3-propanediol are as follows.
Maleic anhydride>succinic acid>adipic acid=sebacic acid>o-phthalic acid.
The activation energies are all found to be 15±0.5kcal/mol, therefore the polyesterification reactions between 2, 2-dimethyl-1, 3-propanediol and various dibasic acids are same reaction mechanism.

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It was found that hexamethyleneadipamide, hexamethylensebacamide and ε-aminocaproic acid were easily polymerized in the solid state at the temperature below their melting points. Detailed investigations were reported here on the heat polymerization of ε-aminocaproic acid in the range of 150-180°C. The following conclusions were deduced from the kinetic results. 1) This reaction seemed to proceed with the first-order reaction. 2) After several hours, the rate constant increased approximately twice. 3) Activation energies for the first and second stages of the ε-aminocaproic acid polymerization were calculated as 38.1 and 32.1kcal/mol, respectively, which seem to be reasonable as the activation energy of heat polycondensation in the solid state. These results gave convincing proofs of our assumption in regard to the reaction mechanism of the polyamidation in the solid state; that is, in ε-aminocaproic acid crystal molecules, having the “zwitter-ion” structure, are beforehand arranged linearly with ionic bonds, and consequently water can be easily isolated to give a linear polyamide. It was concluded that this polymerization was not an apparent but real solid state reaction.

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On the thermal degradation of polyethyleneterephthalate which was completely extracted of the cyclic oligomers, the cyclic oligomers as new product were produced again. The cyclictetramer and the cyclic-pentamer were obtained on the bulk degradation and the cyclic-trimer was on the degradadation in benzene solution. Further, it was found that the favourable reaction temperature for the cyclization without radical degradation was 270-320°C.

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It was studied the graft-copolymerization of methyl methacrylate (MMA) on the polypropylene discharged by Tesla coil.
Alkyl and enyl type radicals were formed on the polypropylene molecule by the action of the electric discharge in the hydrogen atomosphere, and converted to the peroxides by the contact with air.
By heating polypropylene peroxide formed with MMA, graft-copolymers were obtained.
The degree of grafting and graft efficiency depend on the conditions of discharge; the time of discharge, the pressure of hydrogen atmosphere, and the time of contact with air.
To prevent the elevation of temperature during the discharge and the limitation of passage of discharge, the cooling and shaking of the discharge tube gave good results.
At low conversion, the degree of grafting increased with the time of polymeirzation, almost independently on the polymerization temperature, but the graft efficiency decreased with the polymerization temperature.
At high conversion, apparent degree of grafting increased rapidly and popcorn-like product was obtained.

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Polyacrylamide (PAAm) obtained by an anionic catalyst contains two kinds of polymer, that is, a transition polymer and a vinyl polymer. A quantitatative method for the determination of the fraction of these units in the polymer is described. The fraction of transition polymer, as determined by difference from the measured concentration of primary amide groups (contained only in a vinyl polymer), is consistent with the results obtained from the residual nitrogen content (contained only in a transition polymer) in the product obained by hydrolysis of the polymer. This result shows that the fraction of each structure can be quantitatively determined by chemical analysis. Further, the optical density of the IR spectrum of a secondary amide group in a transition polymer shows a good correlation with the fraction of transition polymer determined by chemical analysis. Therefore, the IR spectrum can be used as a simple method for determining fraction of transition polymer.
By experiments on the fractionation of the polymer by water, and from melting-point measurements, it is found that PAAm obtained by a conventional anionic catalyst contains both transition and vinyl structures in one polymer chain.

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The relationship between the structure of the polymer and the polymerization conditions have been studied by using the analytical method described in the previous paper. In the polymerization with sec-BuONa catalyst, a polymer with a large fraction of transition units is produced in high conversion with high catalyst and low monomer concentration. In aromatic solvents, the fraction of transition units in the polymer decreases with increasing solvent polarity. Otherwise, using basic solvents, such as, dioxane, pyridine and dimethylformamide, the amount of the transition unit in the polymer increases as the polarity of the solvent increases. Similar results are obtained when (sec-CuO) ₂Ca is used as a catalyst. However, the structure of the polymer obtained with (sec-BuO) ₃Al is independent of the polarity of a solvent. These results show that the structure of the resultant polymer is mainly controlled by the monomer concentration and by the strength of the catalyst in complex formation with an amide group. In the system for which the moleular weight of the polymer increases as the polymerization temperature is raised and as the degree of conversion is increased, it is supposed that the resultant polymer molecule adds to another polymer molecule.

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It was previously reported that cyclic ethers and maleic anhydride formed a charge transfer molecular complex which initiated the polymerization of cyclic ethers in the liquid state. Maleic anhydride is a useful electron acceptor, but it is very difficult to produce a truly homogeneous solid solution at room temperature and for this reason, it is not suitable to use maleic anhydride for the study of the polymerization in the solid state. The authors examined the solid state polymerizations of trioxane, tetraoxane and N-vinyl carbazole VCZ by gaseous electron acceptors such as chlorine (Cl₂) and sulfur dioxide (SO₂).
Solid-state polymerization of trioxane induced by Cl₂ gas proceeded well at the temperature higher than 25°C similarly to the case of radiation-induced polymerization, and polymer yield was reduced in the solution. The melting point of polymer obtained was 178°C, but the molecular weight is very low owing to the degradation of polymer. Trioxane was also polymerized by SO₂ in the liquid state at higher temperature. N-vinyl carbazole was easily polymerized by Cl₂ or SO₂. Eutectic mixture of trioxane and VCZ was treated by Cl₂, or SO₂ gas to produce a copolymer. From the result of the fractionation, the existence of block copolymer of polyoxymethylene and polyvinyl carbazole was recognized. Tetraoxane was also polymerized by Cl₂ and SO₂ gas in the solid state.
The initiation mechanism was clarified by means of ESR measurement. A singlet spectrum was observed, when VCZ was treated by Cl₂ gas. The spectrum may be attributed to a cation radical of VCZ, which is derived from a charge transfer complex between VCZ and the electron acceptor, i. e., Cl₂ gas. Similar spectra were also observed in the case of iodine, bromine, borontrifluoride and stannic chloride. The spectrum is not changed during the polymerization. This monomer is polymerized easily by cationic mechanism. Therefore, an initiating species may be considered to be a cation radical formed by charge transfer complex between VCZ and electron acceptor.

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Partially carbonylated polyvinylalcohol (PCPVA) wassynthesized from polyvinylalcohol (PVA) and methylvinylketone (MVK) in the presnce of NaOH catalyst. As the result, it was found that the addition of MVK to PVA increased with increasing MVK concentration and lowering the reaction temperature.
PCPVA containing about 20% carbonyl groups is easily soluble in water at room temperature.α, β-unsaturated carbonyl group besides saturated carbonyl group in PCPVA was found by the spectroscopic measurements and its formation was deduced to be due to the dehydration by aldol condensation.
The viscosity change of aqueous solution of PCPVA in the presence of NaOH differed from that of PVA aqueous solution and the difference in behavior was investigated.
As the phase separation of aqueous solution of PCPVA was found at higher temperatures, the relationship between carbonyl group contents and the temperature of phase separation was investigated. It was concluded that the effect of α, β-unsaturated carbonyl group was more important than that of saturated carbonyl group for the factor of the phase separation.

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Three-component copolymerization of vinyl chloride, acrylic acid and styrene was studied in the temperature range from 40 to 70°C in benzene, using azobisisobutyronitrile as initiator. It was found that the rate of copolymerization decreased with the increase of mole fraction of vinyl chloride and styrene in the monomer compositions, and that the mole fraction of vinyl chloride in the copolymers was much less than that in the monomer compositions. Values intrinsic viscosity of copolymers formed were found to be small when the copolymers contained larger amounts of vinyl chloride and styrene. Solubility tests were made on the copolymers.

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The mold shrinkage of polycarbonate (PC) was studied with disks, 4in. in diameter by 1/8 in. in thickness, gated radially at a single point in the edge, 5.2 mm in width by 2.6 mm in depth and 2.2mm in land length, molded with the injection molding machines of plunger or reciprocating screw type. The following results were obtained.
i) The initial shrinkage observed within 30 min after ejection was ascribed to the temperature change of PC from mold temperature to room temperature. The after shrinkage was apparently small as it was diminished by the expansion of PC caused by the absorption of humidity in air. Hence it was possible to estimate the final dimensions of disks from their initial dimensions immediately after ejection. ii) The statistically treated data indicated that PC was moldable within ±0.02% precision in diameter, provided the shape was simple with a uniform thickness. iii) The mold shrinkage varied between 46×10^-4 (mm/mm) and 114×10^-4 (mm/mm) with change in molding conditions. iv) The relationships of mold shrinkage S (mm/mm) with nominal holding pressure P_h, (kg/cm²), stock temperature T_S (°C) or mold temperature T_m (°C) were summarized in the following equations,
S×10⁴=A₁-0.04 P_h (1)
S×10⁴=A₂-0.51 T_S (2)
S×10⁴=A₃ A₃-0.20 T_m (3)
where A₁ was a constant which was characteristic of pressure drop of holding pressure along the flow channel, and A₂ and A₃ were constants. The equation (3) meaned that the disk diameter became larger with increase in T_m. This tendency resulted from the following phenomenon that the cavity dimension expanded to became larger with increase in T_m. v) The effects of both T_S and molecular weight M_v on S were summed up in one single equation as a function of melt viscosity η(poise), i. e. S×10⁴=A₄+3.8×10^-3η, where A₄ was a constant. This result sugested that the change in T_S or M_v gave rise to the change in effective holding pressure. vi) The effect of holding time or feed cushion on S was striking, however the type of nozzle, injection pressure or injection rate did not influence S. vii) Also the mold shrinkage of polyacetal was measured and the distinctions between PC and polyacetal were discussed.

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