Polypropylene used in this study, exhibited no appreciable absorption in ultraviolet and visible regions. The increases of optical density with decreasing wave length in the air was due to light scattering by spherulites in the sample and so it was apparent absorption.When the sample was irradiated by a low vapor pressure mercury lamp under oxygen atmosphere, intense degradation occurred and the shorter the wave length, the greater the degradation. The photodegradation induced by the lights 3650Å, 2537Å, and 1850Å showed strong oxygen dependency and it depended also on the residual ash from polymerization catalyst. On the other hand, if the sample was irradiated by those lights in vacuum, an abnormal “time of exposure-DP curve” was obtained. The apparent degree of polymerization, estimated from the solution viscosity, increased with the exposure time in the early stage of irradiation. This increase was attributed to the photochemical crosslinking between polymer chains. However, on further irradiation, the extent of crosslinking increased so much as to separate the gel formed by the highly crosslinked polymers, andthe apparent degree of polymerization of polymer molecules dissolved in solution decreasedwith the time of exposure. From the above mentioned experimental results, it becameclear that the degradation in oxygen atmosphere was photooxidative degradation sensitizedby residual ash and there was a possibility of photocrosslinking when the irradiationwas carried out in vacuum.

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To obtain a knowledge of the reaction mechanism of heterogeneous polymerization of vinyl monomer, the effect of stirring speed on the rate of polymerization of methylmethacrylate in aqueous medium has been investigated. From the experimental results, it was found that 1) the size distribution frequency of polymer particles was monodisperseat 200-700rpm until high conversion, but it was polydisperse at 0-150rpm, 2) the number of particles per ml was almost invariable during polymerization at 200-700rpm, but it decreased with polymerization time at 0-150rpm, and 3) new small particlesappeared when the diameter of polymer particles have grown up to 3000-4000Å andyet unreacted monomer droplets have remained in aqueous phase.

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Polystyrene and polymethyl methacrylate in solution were degraded by high frequency oscillating ions at 33kc. The effects of voltage between electrodes, of conductance of reacting solution and of salts added as oscillating ion vibrator on degradation were studied.
As results, the degradation constant k_d was expressed as follows, _??_(a and b are constants, V is the voltage between electrodes. C is the conductance of reacting solution.)
where, k_d is defined as follows, log [η]/[η] 0=k_d·t or log P/P0=k_d·t And, the difference of ionic species seems to have little influence upon the degradation rate, so far as the conductance of solution and degradation rate is expressed as above equation.

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Polymerization of acrylonitrile by oxygen-bisulfite redox initiator was investigated in the presence of cupric ion. It was found that the polymerization was inhibited by oxygen at the concentration of bisulfite below 1.0×10^-3mol/l, whereas when the concentration of bisulfite was higher than 3×10^-3mol/l, the polymerization was accelerated by the presence of oxygen. But the polymerization of acrylonitrile by this redox system stopped atlow conversion. This is probably due to the strong tendency of formation of an addition compound of bisulfite to the monomer.
To improve the polymer yield, the effect of polymerization conditions on it in oxygen atmosphere was investigated, and it was found that (1) the polymerization proceeds to high conversion when the bisulfite is added continueously during the polymerization and the pH of aqueous medium is kept to about 6, (2) the rate of polymerization shows a maximum at about 1: 8 volume ratio of monomer to water phase, (3) the rate of polymerization comes to the highest at 40-50°C, (4) the effect of pH is very complicated; the rate of polymerization shows a maximum at pH 6 in the case of continueous addition of bisulfite during polymerization. But when only initially added bisulfite is used, the rate of polymerization passes a maximum at pH 4 and no polymerization takes place at pH 6.

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We analytically made a close examination of the usual methods extruding melt through a circular nozzle, the very important ones to obtain flow characteristics of molten high polymers. We proposed a new method and investigated it by measuring the pressure distribution along the wall of the nozzle.
When polypropylene on the market was extruded through the nozzle of 2mm/diameter at 188, the pressure distribution along the wall of the nozzle become a smooth curve in most parts except the downstream region which reached to: equilibrium state. When we calculated the shearing stress at the wall of the nozzle, R, by the following formula:_??_R: radius of the nozzle
ξ: pressure grade along the wall of the nozzle
the value almost coincided with that of Bagley's method for the end effect correction.
Moreover the experimental existence of the pressure acting on the wall at the end, P_RL.showed analytically that the normal stress difference along the wall of the nozzle, (Δσ₁₁) R could be approximately calculated by the formula:(Δσ₁₁) R=P_RL (1+dln P_RL/2dlnτR). The value of (Δσ₁₁) R, according to this method, is a little less than that of Philipoff's method and much more than that of Metzner's. When we calculated the internal recoverable strain, S, it abruptly approached to the constant value (s≈13) after the melt fracture had begun.

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The surface texture of melt-grown polypropylene spherulites was studied by electron microscopy. The spherulites containing crystals of the β-modification are composed of lath-shaped lamellar crystals doing preferred growth along the radial direction and a little crystals growing along the tangential direction of the spherulite. The spherulites of the β-modification have the characteristic leaflike texture which grows with a spiral form be-ing initiated by the formation of some nuclei. It can be observed that each broad lamella within the spherulite grows accompanied with twist of lamella toward the periphery of spherulite from the center of spiral. Owing to the reason that lamellar crystals grow with a spiral from, it was suggested that the crystal structure of the β-modification proposed until now is necessary to be reinvestigated. It was difficult to obtain well defined spherulitic crystals from thermally decomposed polypropylene by melt-growth, but two types of morphologies of the γ-modification were discriminated. One of them is the lathshaped lamella which is similar to that of the α-modification, and the other is the extremely broad lamella. The reason for the formation of the latter broad lamella is due to the fact that the molecular chains are not folded within the lamella in this case.

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The statistically designed experiments were carried out to study the effects of molding conditions, molecular weights and synthesis methods on a birefringence, the heat shrinkagein flow at 180 and the Taber abrasion of the injection molded polycarbonates. The goodcorrelations between the birefringences and the heat shrinkages were found. A birefringencewas the relative index representing a degree of frozen orientation. The frozen orientationwas storngly affected by the molding temperature and molecular weight, and slightlyaffected by the holding pressure, but not affected by the mold temperature and injectionrate. The polycarbonate synthesized by the trans-esterification process showed strongerbirefringence compared with the one synthesized by the phosgenation process. The frozenorientation was formed during packing. The characteristic birefringence patterns wereresulted from the back-flowing of the polymer in the mold cavity due to the shortage ofthe holding time. One could determine the gate sealing time by utilizing this phenomenon.The amount of the Taber abrasion was affected by the frozen orientation. From the Taberabrasion tests, the frozen orientation was supposed to be also in the surface layers (7microns) of molded specimen.

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Various samples of poly-a-methylstyrene (p-α-MeSt) with different molecular weights were polymerized anionically through use of a bifunctional initiator, sodium-naphthalene. Two samples of them were mixed with various compositions so that the average molecular weight and molecular heterogeneity of the mixture were varied over a wide range. The effect of the molecular heterogeneity on the K-value obtained from Stockmayer-Fixman plot and the Huggins constant κ' was investigated. It is pointed out theoretically that the Stockmayer-Fixman plots of blends are meaningless unless some special conditions are satisfied. This was confirmed by the experiments on the blends. The Huggins constant κ' showed a marked dependency on molecular weight. For the living polymers we used, it decreases with increasing molecular weight from 0.9 to 0.3. On the other hand, κ' for the blends ranges mostly from 0.3 to 0.4. It is expected therefore that slight changes of κ' with molecular weight obtained so far might be attributable to the polydispersity of the samples used. The unperturbed chain dimension of P-α-MeSt is also discussed briefly.

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Polycrotonic acids (PCA) were prepared by radical polymerization of crotonic acid (CA), iso-crotonic acid (i-CA) and ethyl crotonate (EC). PCA's prepared from CA and i-CAshowed nearly the same potentiometric titration curves, and were stronger acids thanpolyacrylic acid (PAA), but the PCA derived from EC showed remarkably differentpotentiometric and conductomftric titration curves.
Polyvinyl acetic acid (PVAcA) prepared by radical polymerization gave nearly the same titration curves as the special PAA's which were polymerized in the presence of strongrepulsion between side groups of the monomer units.
Polyitaconic acids (PIA) were treated with concentrated sulfuric acid to obtain decarboxylationproducts (DC-PIA) with a possible structure;-CH₂-C (=CH-COOH)-. The DCPIAderived from the PIA polymerized in 20% aqueous solution gave nearly the sametitration cruve as PVAcA, but the DC-PIA derived from the PIA polymerized in diluteaqueous solution of pH=6 was a considerably stronger acid than PVAcA.
Such differences between variously prepared PCA's or DC-PIA's may be mainly attributedto their different stereo-structures.

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Changes in molecular conformations of poly-γ-methyl-L-glutamate (PMLG) in dichloroacetic acid (DCA), m-cresol, dichloroacetic acid-1, 2-dichlroethane (DCE), and trichloroacetic acid-acetic acid were studied as a function of temperature by optical rotatory dispersion measurements at 10°C to 50°C, and by intrinsic viscosity measurements at 20°C to 65°C. The results obtained were compared with that for poly-γ-benzyl-L-glutamate (PBLG). According to the experiments, the following conclusions were obtained. PMLG, in DCA-DCE and trichloroacetic acid-acetic acid systems, transforms from coil to helix with increasing temperature by the inverse transition mechanism as found for PBLG in DCA-DCE mixture. The enthalpy of transformation ΔH for PMLG estimated in DCA-DCE system is 75±10 kcal/mole and is considerably small compared with the values, 95-110±15kcal/mole, for PBLG. The helix stability of PMLG is lower than that of PBLG and it is pointed out that the number of residues which co-operatively contributes to transformation is smaller for PMLG (88 residues) than for PBLG (100-110 residues).

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