Unfractionated polyacrylonitriles were dissolved in 70% nitric acid. These solutions were extruded into a dilute nitric acid solution. After the coagulation they were scored. Relations between the stretchabilities of coagulated threads thus obtained and those of their component polymer species were investigated. The stretchability of the polymer species was measured under the same spinning condition by using the fractionated samples. The stretchability distribution curves for many unfractiovnated polymers were made from the molecular weight distribution curves by the use of the obtained stretchabilitiy-molecular weight relations. It was found that the maximum heat-stretchability of unfractionated polymer, was given by the weight average of those of the component species.

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The infrared absorption of OH groups of thiolignin-SBR (styrene-butadiene copolymer) coprecipitate is situated at the higher frequency region than that of thiolignin itself, or that of the lignin in dry compounded lignin-SBR mixture. As reported previously, this fact means that some OH groups of lignin in the coprecipitate are set free from the hydrogen in lignin itself, and are able to interact with π electrons in SBR. However, if the same coprecipitate is kept in hot water, or hot pressed in the moistened state, the infrared absorption of OH group shifts near to that of lignin itself, and the reinforcing action of lignin is markedly decreases. Furthermore, the apparent density of the secondary bond ν₂ is estimatedfrom the difference of the network densities calculated from modulus and from degree of swelling. From the variation of ν₂ values with temperature the energy of this secondary bond is calculated approximately as 1.3kcal/mol, which is nearly equal to the proton-π electron interaction energy estimated from model experiment reported previously. This ν₂ value is larger than those other fillers, and it increases rapidly when the lignin content exceeds ca. 25phr, suggesting that the hydrogen bond existing among lignin particles also contribute to the reinforcement.

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Thiolignin acts as an excellent reinforcer also for acrylonitril-butadiene copolymer (NBR). As in the case of thiolignin-SBR system, investigated in part 1 of this series, the existence of strong affinity will be expected between OH group in thiolignin and C=C double bond or C≡ N triple bond in NBR. The hydrogen bond between OH group and C≡N group was in vestigated by measuring the infrared absorption of OH group in CCl₄ solution, using isobutyronitril as a model for NBR and the same lignin model compounds having OH groups as used in part 1 of this series. It is concluded that strong bonds of 3-4kcal/mol are formed between thiolignin and NBR. Furthermore, the infrared absorption of OH group in lignin-NBR coprecipitate was investigated and the characteristic absorption band was observed, which is presumably due to the interaction between OH group and C≡N group, being different from that of lignin itself or lignin-SBR coprecipitate.

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A polystyrene sample, which had been distributed by “The committee on molecular weight and molecular weight distribution in Japan” for co-operative measurements of the molecular weight distribution, was fractionated by the successive precipitation method using toluene as solvent and polyethylene glycol as non-solvent. It was characteristic of the phase separations in this ternary system that the separated two phases were liquid and the concentration of the polymer in the more concentrated phase was lower than that obtained with other systems of solvent and non-solvent usually used. These features in this system allows a sample of polystyrene to separate into many small fractions and thus this system may be used for precise fractionation of this polymer.
Thirty five fractions were separated from 5 g. of the sample, and the first two fractions of them were refractionated. The molecular weight distributions of the sample calculated from the data obtained before and after the refractionation showed an appreciable difference. This result indicates that a sigle successive precipitation is not sufficient for the precise determination of the molecular weight distribution, even if the number of fractions was large.
The results were compared to those obtained on the same sample by other methods.

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Polymerization of vinyl acetate in methanol initiated by α, α′-azo-bisisobutyronitrile is performed in a sealed tube. The effects of polymerization temperature and concentration of monomer, initiator and water on inhibition period, rate and degree of polymerization are investigated. Inhibition period decreases as the temperature and the initiator concentration increases. The rate of polymerization is independent of the water content, and becomes greater by higher concentration of monomer and initiator and higher temperature. The degree of polymerization is higher by higher monomer concentration, lower temperature and initiator concentration and greater content of water. The relationship between the degree of degradation by saponification and conversion is almost independent of polymerization conditions except monemer concentration. The ratio of ₁₀₀PA and ₀PA, which are the extrapolated values of polymerization degree of polyvinylalcohol to 100 and 0% conversion, is almost independent of the conditions of polymerization. The average value of this ratio is 0.63.

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It has been found that both the polyvinyl acetate polymerized by ultraviolet irradiation and the polyvinyl alcohol obtained by saponification of the above polymer with alkaline have a characteristic absorption at 245mμ. These results suggest that these two polymers contain acetophenone residue. It has also been found that this polyvinyl alcohol contains 1.33 bromine atoms per 1, 000 monomer units and that these polyvinyl acetate and polyvinyl alcohol are able to initiate the polymerization of acrylic monomer by ultraviolet irradiation to form block co-polymers.

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Copolymer of allyl alcohol/SO₂ was easily obtained by per-sulphate initiator in the solution where SO₂ was dissolved, using dimethyl sulfoxide, dimethylformamide, dimethylacetamide or water as solvent.
The derivatives of allyl alcohol such as allyl ether allyl ester, could be also copolymerized with SO₂, but allyl cyanide, allyl chloride and allylamine couldn't be copolymerized. Copolymerization of allyl alcohol and SO₂ proceeded rapidly. Optimum temperature and ceiling temperature of polymerization exists at 20-25°C and 55-60°C respectively. Copolymer was rigid and melted with decomposintion at 160-170°C. Composition of copolymer was assumed as following formula from elementary analysis. A small amount of-S-S-linkage was found in the copolymer by infra-red spectrum.

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