By applying the theory proposed by Kamide-Kawai for analyzing the intrinsic viscositymolecular weight relationship to cellulose nitrate, the following informations on molecular constants were obtained.
(1) Existence of draining effect cannot be ignored, whenever the theories of Flory-Fox, Kurata-Yamakawa and Kurata-Stockmayer-Roig are used as the starting models. The estimated values of the draining parameter Δ are 0.20-0.24 for nitrogen content N=12.02% and 0.42-0.46 for N=13.79%. The latter coincides with the authors' conclusion in the previous paper.
(2) The values of Flory constant K evaluated through the consideration of the draining effect are 1.15-1.48×10^-8 for N=12.02% and 1.16×10^-3 for N=13.79%.
(3) The flexibility of polymer chains, represented by (r²₀/r²₀, f), where r²₀ and r²₀, f are the end-to-end distance of the real polymer chain and of the postulated polymer chain with free internal rotation, is not significantly changed by the increase of the nitrogen content. The estimated values are in the same order of magnitude as those of the vinyl-type polymers.
(4) Molecular weights of statistical segment Ms are 1.62×10³ for N=12.02%, 1.81×10³ for N=13.79%. Lengths of the statistical segment a′ are 34.62 Å for N=12.02%, 34.83 Å for N=13.79%.

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In the copolymerizationo f butadienea nd isoprene by Al (C₂H₅) ₃TiCcal₄ta lyst, followingr esults were obtained. Al/Ti mole ratio, in the range of 1.25 to 1.50, had no effect on the monomer reactive ratios (both r_B and r_I were near unity), but the reaction rate of copolymerization failed markedly with changing Al/Ti ratio from 1.25 to 1.50. Copolymers consisted of either benzene soluble and insoluble parts, their composition and microstructure being almost the same each other. By the fractional precipitaion method, the benzene soluble part was fractionated into several fractions, all of which had the same microstructures but the differentc ompositionsa nd viscosities. The microstructureso f butadiene and isoprene unit in the copolymersw ere same as that in the homopolymeros btained under the same polymerization condition. The intrinsic viscosities of copolymers were smaller than those of homopolymers and that of 50/50 copolymers was the minimum.
From these results, it was concluded that the above results gave a support to the assumption on the multiplicity of active sites in Ziegler type catalysts proposed in the previous papers. In the copolymerizationo f butadiene and isoprene, t he stereospecifica ddition of the entering monomer did not depend on the kind of the monomer unit of the growing chain end. The cross-transfer reaction occured more easily than the transfer reaction towards the same monomer as the growing end.

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The monomer reactivity ratios for the copolymerization of tetrahydrofurfuryl acrylate (TFA) with styrene (St) at 70deg;C were found to be 0.485 (r_T) and 0.501 (rs) and that for the bulk copolymerization of TFA with acrylonitrile (AN) at 70deg;C were 0.665 (r_T) and 0.689 (r_A).
Tensile strengths, elongations, softening points and solubilities for the films of poly (TFAco-St), poly (TFA-co-AN) and poly (TFA-co-St-co-AN) were measured. When the films of these copolymers were baked at 150deg;C for 15min, many of these were converted to films insoluble in organic solvents.

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Polymerization of acetaldehyde was carried out by using metal sulfates as catalyst and dependency of catalytic activity on the acidity of metal sulfates was studied.
Tri-valent metal sulfates containing water of crystallization could polymerize acetaldehyde, but di- and mono-valent metal sulfates could scarcely do, when they were not calcinated. Acetaldehyde was polymerized with di-valent metal sulfates which were calcinated in suitable condition, but was not polymerized with calcinated mono-valent metal sulfates. Such sulfates that could polymerize acetaldehyde indicated acidic color for ρ-dimethylamino benzene (pKα =3.3) and it is considered that the existence of acidic point having acidity function below 3.3 is necessary for polymerization of acetaldehyde with solid catalyst. In the polymerization of acetaldehyde with metal sulfates, the conversion is lower than that with metal sulfate-sulfuric acid complexes and the obtained polymers were amorphous. Polymerizations with some solid catalysts other than metal sulfate were studied also.

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Polyoxymethylene was irradiated at various temperatures from-196deg;C to+200deg;C and the decomposition, the viscosity decrease and the thermal stabilization were examined.
Decomposition of polyoxymethylene was accelerated by irradiation at high temperatures. The gases evolved (mainly formaldehyde) also accelerated the decomposition rate under irradiation. Viscosity of polyoxymethylene was always decreased by irradiation in vacuum at temperatures from-196deg;C to+200deg;C. The rate of decrease of viscosity was faster at higher temperature. Polyoxymethylene dihydrate was thermally stabilized by irradiation. The thermal stabilization rate was also fast at high temperatures. The thermal stabilization could not be achieved, if the formaldehyde gas existed during irradiation. The saturation value of the formation of the stable polymer was low in the case of irradiation at -196deg;C. After-effects of irradiation on the viscosity or on the stability of the polymer could not be clearly observed even in the case of irradiation at-196deg;C.

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The homogeneous polymerization of acrylonitrile in dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), dimethyl acetamide (DMA) and ethylene carbonate (EC) initiated by azobisisobutyronitrile was investigated by dilatometric techniques under homogeneous conditions. The observed dependence of the rate and the degree of polymerization on the polymerization conditions in the above-mentioned solvents is explained consistently by assuming the kinetic scheme which involves the reactions of relatively unreactive radicals derived from the solvents by chain transfer. Besides the termination reaction of growing radicals by primary radicals may also take in consideration to explain the results in DMSO and EC.
Chain transfer constants of DMSO, EC, DMF and DMA for polyacrylonitrile radicals at 50°C are found to be 2.9×10^-5, 3.3×10^-5, 27.8×10^-5 and 50.5×10^-5 respectively.

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The polymerization of acrylonitrile in dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), dimethyl acetamide (DMA) and the aqueous solution of ethylene carbonate (EC+H₂O, EC 10 volume %) initiated by ammonium persulfate is investigated by dilatometric techniques under homogeneous conditions. The following results are obtained.
1) The rate of polymerization in DMSO is proportional to the square root of the ammonium persulfate concentration.
2) The values of (k_td+k_tc/2)/k_p² in the ammonium persulfate initiated polymerization in DMSO (40°C 18.2, 45°C 15.0mol/sec/l) is less than those in the azobisisobutyronitrile initiated polymerization in the same solvent. This behavior is explained in terms of reduction in the rate of termination. The reduction in the rate of termination may be due to the mutual electrostatic repulsion of the chains caused by the presence of electrically charged end groups arising from initiation by the sulfate ion radical.
3) Activation energies of polymerization in DMSO, DMF, DMA and EC+H₂O (EC 10 volume%) are 16.5, 17.6, 15.9 and 19.5kcal/mol respectively.
4) Ammonium persulfate decomposes more rapidly in these organic solvents than in water. The rate of decomposition is found to increase in the following order, EC+H₂O<DMSO<DMF<DMA. The mechanism of decomposition is discussed.

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The graft copolymerization of methyl methacrylate and methyl acrylate on dialdehyde starch (DAS) were carried out under various conditions.
The ceric salt, persulphate and “Silubrite” bleaching agent containing sodium chlorite as main component were effective as polymerization catalysts and the grafting efficiency as high as 60-95% was obtained using such catalysts.
DAS itself showed catalytic activity, though having long inductive period.
Apparent activation energy of the graft copolymerization with methyl methacrylate using ceric ammonium nitrate was about 10kcal/mol and initial rate of the graft copolymerization was proportional to the square root of DAS concentration.
On basis of these results, mechanism of the graft copolymerization was discussed.

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The graft copolymerization of acrylates on cellulose acetate were carried out in solution system, and the effects of initiator, solvent, polymerization time, temperature and addition of water were studied. The results were as follows:
1) Ammonium persulphate (APS) and ceric ammonium nitrate were used as initiator, and especially the latter had a strong catalytic activity.
2) There is a maximum degree of grafting in a certain region of catalyst concentration.
3) Addition of water to the system gives remarkable effect on grafting.
4) Dimethylformamide (DMF) and acetic acid are effective solvents for graft-copolymerization.
The reactivity of monomer for graft-copolymerization is as follows;
n-butylacrylate>ethylacrylate>methylacrylate
Some physical properties of the graft-copolymer were determined and discussed

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Thermal degradation products of polystyrene were analyzed by a gas chromatograph. Polystyrene was pyrolyzed in a vacuum and in the air in the Madorsky-type pyrolysis apparatus, slightly modified by making the preheated electric furnace move quickly on a rail to assure rapid heating to the definite decomposition temperatures.
The monomer yield in the pyrolysis products of polystyrene increases with heating temperature in the range of 300°C to 420°C, but no difference in the monomer yield is observed in a vacuum and in the air at the same temperature. Benzaldehyde and acetophenone are detected beside the monomer in the pyrolysis product in air.
Polystyrene was also pyrolyzed in a pyrolysis apparatus of glass-tube type, described in the previous paper, and the influence of the recurrency in this apparatus on thermal degradation was ascertained.
These results show that the styrene monomer is produced by a unzippering type depolymerization mechanism. Since the zip length becomes longer with degradation temperature. the monomer yield of styrene increases with temperature.
The oxygenated products of pyrolysis in the air are proposed to be formed by the transfer of tertiary or secondary hydrogen atoms after the formation of terminal carbonyl group, but as the depolymerization mechanism is not involved in these reactions, the oxygene in the air has not remarkable influence on the reaction of splitting off of the styrene monomer.

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To investigate the mechanism of rapid thermal degradation at high temperatures, a pelletstate of polymer is dropped suddenly into a preheated quartz tube, and the degradation products are sweeped directly into the column of a gas chromatograph by nitrogen gas for analysis.
Using this method, the mechanism of thermal degradation of styrene-acrylonitrile copolymer, especially the influences of copolymer composition and the decomposition temperature on the yield of each monomer based on the monomer unit in the copolymer are studied. The copolymer composition and the temperature within some range show no remarkable influences on the monomer yield of styrene. Therefore, if the copolymer was pyrolyzed at about 600°C, the styrene content in the pyrolysis products would be utilized for the measure of the composition of parent copolymer.
The monomer yield of acrylonitrile decreases with acrylonitrile content in the copolymer, and is affected greatly by the structural distribution of monomer units in the molecular chain. Therefore, some informations on the structural distribution of copolymer can be obtained by this method.

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Monomer reactivity ratios (MRR) for acrylonitrile (AN)-sodium allyl sulfonate (SAS) were determined by carrying out solution polymerization (initiated with azobisisobutyronitrile at 60°C in dimethyl sulfoxide) and suspension polymerization (initiated with K₂S₂O₈-NaHSO₃ at30°C in water).
The MRR values estimated were γ1 (AN) =0.69±0.05, γ2 (SAS) =0.18±0.05 for the solution polymerization and γ1 (AN) =4.94±0.06, γ2 (SAS) =0.07±0.06 for the suspension polymerization. From the MRR values for the solution polymerization and Q (=0.44) and e (=1.2) for AN, Price-Q and -e values for SAS were also calculated to be 0.11 and -0.24 respectively.
The results were discussed mainly in terms of the polarity of the monomers.

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The mechanism of the graft copolymerization by preirradiation technique in the homogeneous system was studied. Polymethylmethacrylate (PMMA) powder, which was irradiated with λ-rays from 60 Co in the air, was dissolved in deaerated styrene-benzene solution.
The rate of polymerization of styrene in this system was measured dilatometrically. The rate was proportional to the monomer concentration and the square root of PMMA peroxide concentration.(The content of peroxides which were formed in PMMA by irradiation in the air was measured by iodometry.) From these results it is concluded that the mechanism of the polymerization of styrene in this system is the same as that initiated by conventional peroxide initiators. The efficiency of grafting (ratio of grafting polystyrene to the total polystyrene) measured by fractional precipitation was approximately 50%.

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