X-ray diffraction method was applied to measure the elastic modulus of polymer crystals in the direction of chain axis. Highly oriented filaments or fibers were mounted in a stretching clamp and the shifts of 2θ angles of the meridial reflections were measured under constant load. The modulus for the crystalline region was calculated, using a simple series model, from the initial slope of the stress-strain curve for the lattice.
It was found that polyethylene (PE) and polyvinyl alcohol (PVA), both of which are characterized by their fully extended fiber structure, had such high E-values as:
It should be noted that values for PE and PVA agree within an experimental error. This may be a proof that the interchain cohesion has no influence on the lattice extensibility in the chain direction.

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If the polymer chains in crystalline region have helical configurations, moduli of their crystalline regions in the direction of orientation (E) are expected to be small by simultaneous internal rotations of the chains by extension.
By the X-ray method as reported in part I, the following E-values for isotactic polypropylene (Isot. PP) and polyoxymethylene (POM), both of which are characterized by helical chain configurations in the crystal, were obtained:
Both values are much smaller than that for polyethylene (240×10⁴ kg/cm²), but they are ten times as large as those obtained by Dulmage and Contois for the polyesters (4-7×10⁴ kg/cm²) with fiber period contractions of about 15-20%. Lattice extensions in all measurements were shown to be almost completely recoverable. In the case of POM, a point of inflection was observed, both for the lattice and the specimen, in the stress-strain curve at the corresponding stress.

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Elastic moduli of the crystalline regions (E) of highly oriented specimens of polyethylene terephthalate (PET), polyvinylidene chloride (PVCl₂) and cellulose (Cell.) were measured by X-ray method as reported in part I:
The value for PET is about half of that (140×10⁴kg/cm²) obtained by Dulmage et al. The stress-strain curves for lattice and specimen for PET show the same characteristics as observed for polyoxymethylene in part II.The somewhat low modulus for PVCl₂ may be due to its contracted chain configuration in the crystal. The result for Cell, is in good agreement with those reported by other authors.

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It is known that the viscosity-molecular weight relationship obtained experimentally depends upon the molecular weight distribution of polymers. This dependence originates in the fact that the molecular weight determined experimentally is not the viscosity average molecular weight M_v, but the weight average molecular weight, M_w, or the number average molecular weight M_n. We are concerned in this paper with the correlation of M_v and M_w or M_n regarding the width of molecular weight distribution and with the extent of fractionation of polymer sample to obtain a plausible viscosity-molecular weight relationship. Further, it was discussed about the measure of the width of molecular weight distribution which was reasonable in such case and it was found that the ratio M_w/M_n was the most suitable one. The dependences of sedimentation constant and diffusion constant on the molecular weight were also discussed by similar manners. All of these calculations were carried out by making use of the molecular weight distribution curves by sedimentation velocity method.

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The gamma-ray induced graft copolymerization of methacrylic acid on polyethylene film by a pre-irradiation technique under atmosphere has been studied. Both radicals and peroxides, which were produced during the irradiation in air can initiate graft copolymerization, but when the irradiated polymer is stored for long period under air at 25°C before grafting, the trapped radicals decay gradually and then grafting may be induced by peroxides. Degree of grafting give in the grafting induced by both trapped radicals and peroxides was not proportional to the total dose, but it was approximately proportional to the total dose if the initiator is peroxides only. Therefore, the degree of grafting in the former case was 4-5 times higher than that in the latter case in the irradiation temperature of 0°C to -78°C and there was very little difference between both cases above about 40°C. The activation energy of the grafting initiated by the peroxide was 22 kcal/mol. The comparative study of the decay of grafting after storing in air between low pressure polyethylene and high pressure polyethylene indicated that grafting arises from the trapped radicals did not occur in high pressure polyethylene. It was confirmed from this investigations that the trapped radical was more stable in a low pressure polyethylene than in a high pressure one.

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The gamma-ray induced graft copolymerization of styrene on cellulose acetate fiber by a pre-irradiation technique in air has been studied. The maximum degree of grafting was not affected by a change in the storage condition of the irradiated fibers, but slightly increased with the irradiations temperature under same irradiation dose in the temperature region of -78°C to 110°C. These results indicate that this grafting is initiated by a fairly stable peroxide produced in the irradiated fiber. Although the maximum degree of grafting increases with the irradiation dose, the rate of the grafting decreases with irradiation dose. These phenomena would be due to decomposition of peroxides in the irradiated specimen by further irradiation. The grafting was performed within 60min above 65°C and the total degree of grafting decreased with the grafting temperature. Dependence of the grafting temperature on the total degree of grafting was discussed. The activation energy of peroxide decomposition was about 25 kcal/mol.

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The transition polymerization of methacrylamide by basic catalyst is studied. It has been reported that poly-β-alanine is produced in high yield by transition polymerization of acrylamide, but the transition polymerization of methacrylamide is very slow. In this paper, it has been found that poly-β-methylalanine is obtained from methacrylamide in high yield by using sodium t-butoxide or metal sodium as catalyst in non-polar solvent without alcohol. The structure of resultant polymer is confirmed by infrared spectra. Comparing with polyte-alanine, poly-β-methylalanine has a low molecular weight. The resultant polymer catalyzed by sodium t-butoxide in non-polar solvent has higher crystallinity than that in polar solvent.

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