The effect of annealing on the morphology of polyvinyl alcohol (PVA) single crystals has been studied by electron microscope and small angle X-ray diffraction. When the single crystals are heated at 200-220°C, particles disappear which are mainly attached to the longer sides of the crystals. Granular part of the crystal, outlined by a form similar to that of the crystal itself, has a tendency, after annealing, to become flat. If the single crystals are heated at 230°C, corrugations disappear and holes develop within the lamellae. The holes are oval in shape and lie along a line forming an angle of 25-30° with the longer side. Electron diffraction patterns from the crystals annealed at 230°C show that all reflections excepting the (101) reflection tend to disappear as a result of annealing, showing that molecular axis rotates during annealing. It is recognized that an increase in the long period occurs when single crystal mats are heated in air at a temperature above 220°C.

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Morphological changes accompanying the dissolution of single crystals of polyvinyl alcohol (PVA) are examined by electron microscope. When PVA single crystals are heated at 100°C in water, partial dissolution occurs on the border around the original crystal. The dissolution results in either serrates or linear borders. The dissolved parts are composed of PVA of lower molecular weight than the residual and have lower absorption intensities in a color reaction of PVA with iodine than those of whole crystals. Partially saponified PVA can be crystallized in the form of superposed lamellae, on the edge of which many particles attach. Heating at 65°C in water results in complete dissolution of the particles. It is probable that the particles are composed of PVA of lower saponification degree than the lamellar parts. These results indicate that various kinds of fractionations occur when single crystals are formed.

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The relations between some physical properties and compositions of polypropylene
(PP) -polyethylene (PE) blend polymers were investigated. It was observed that crystalline structure of PP in undrawn blended fibers (quenched) changed from smectic to monoclinic type, and the crystallinity increased with increase of PE, independently of the blending ratio. These changes gave influences on mechanical properties, especially Young's modulus and yield point stress of undrawn fibers. The orientation of PE crystallites varying with PP/PE ratio was used to find how PP and PE disperse.
Drawn fibers showed abnormal mechanical properties over the range of 30 to 50% of PE; namely, in this range elongation and knotting tenacity showed maxima. while Young's modulus changed almost lineary with the percentage of PE.
PP/PE blended fibers seem to consist of continuous PP and PE fibrils isolated from each other, and abnormal behavior in mechanical properties may be explained by considering the slipping between PP and PE fibrils in a non-compatible state.

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This paper is concerned with isothermal crystallization kinetics of isotactic polyproplyene with the viscosity-average molecular weight M_v from 3.2×3 to 1.02×10⁶ studied by polarizing microscopic method in the range of temperature between 120°C and 160°C. It was ascertained from the measurements of infra-red spectra, density, melting point and heat of fusion made on the samples annealed to their maximum crystallinities that the tacticity was of the same order for every sample investigated. The previous thermal history, fusing and crystallization conditions were examined in detail by preliminary experiment. The rate of nucleus formation in polymer fractions followed a first order rate law with a rate constant ν. ν varied little with molecular weight, it's distribution and the number of the repetition of filtration of polymer solution through sintered glass filter to remove the impurity, but it stron gly depended on the crystallization temperature. Since the quantity νt>>1, parameter n=3.0-3.5 appearing in Avrami's equation obtained in the preceding paper (This journal, 22, 597 (1965)) was confirmed on the basis of the kinetics of spherulitic crystallization. Radius of a growing spherulite increased linearly with time in the process of crystallization. The growth rate G was constant at constant temperature for specific specimen irrespective of the time at which the spherulite nucleated. Maximum value of G was obtained for fraction of M_v 4×10⁵ at 130°C and 140°C. Comparring at the corresponding degrees of undercooling, G became larger for smaller molecular weight. A good fit of experimental data on growth rate to the secondary two-dimentional nucleation theory was obtained. Structures of spherulite changed with molecular weight and crystallization temperature. In general, more regular fine radiating fibrils were observed for polymer of higher molecular weight. Spherulitic crystallization did not occur below 130°C for polymer of molecular weight of 3.2×10³. Sign of birefringence in the radial direction of spherulite of fractions of M_v 8.6×104 was negative at the crystallization temperature above 140°C. On the other hand, mixed type of spherulite was obtained below 130°C. Sign of birefringence gradually changed between 130°C and 140°C. Spherulite of fraction having M_v=2.4×10⁴ had possitive sign in the range 120°C to 150°C.

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For observation of the transition phenomena in polymers, refactometer with heating apparatus was made. Refractive index of polymer specimen can be measured from room temperature to 300°C by this instrument.
The merits of the measurement by this instrument are following:
1) measured data are independent of the microscopic void in the sample, so the preparation of sample is done very easily,
2) the weight of sample needed for one measurement is only about 10mg,
3) refractive index which is one of the material constant, can be directly measured without any calculation.
The examples of the application are following:
1) observation of the melting process of various poly-olefines,
2) determination of the amorphous density of the isotactic polypropylene at roomtemperature,
3) determination of T_m and T_g for polyvinyl alcohol.

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Various properties of polyethylene resins from various sources are measured. It is shown that by their properties, they are separated into two groups of low density polyethylene, and high density one. Meltindex, stress-cracking resistance, density and ultimate strength are found to be related primarily to intrinsic viscosity (molecular weight).
It is suggested from this study that such new polyethylene resins having the low density and high molecular weight, or the high density and low molecular weight will be desirable.

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Temperature dependencies of Charpy impact strengths on plastic-rubber blends were measured in order to gain insight into the toughening mechanism in these systems. Results were generalized phenomenologically in relation to the temperature dependencies of dynamic-mechanical properties of these systems. Blends of PVC and rubbers with various chemical structures and several ABS-polymers were investigated.
In all systems, Charpy impact strengths began to increase at nearly the glass-transition temperature (T_g) of the rubber component with increasing temperature. They continued to increase logarithmically against the temperature axis. These trends were expressed by the following equation.
l-A exp (-B/T),
where l is Charpy impact strength, A and B are constants, and T is the absolute temperature. This equation is applicable between T_g's of plastic and rubber components.
The increasing tendencies of impact strength with increasing temperature were depressed mainly by the decrease in of adhesive force between both phases.
Toughening mechanism and the ways of increasing impact strength in these systems were discussed.

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Methacrylamide was polymerized by a basic catalyst and the result was compared with transition polymerization of acrylamide. 1) The rate of polymerization of methacrylamide was very slower than that of acrylamide. 2) The intermolecular proton transfer should be more favoured on methacrylamide than acrylamide and methacrylamide might be mainly polymerized stepwisely in toluene. On the other hand, in the case of the transition polymerization of acrylarnide the polymer might be predominantly formed by the chain reaction in toluene. 3) When methacrylamide was polymerized by sec-BuONa in polar solvents, such as pyridine, dimethylformamide and nitrobenzene, the monomer and polymer were hydrolyzed, while in the case of acrylamide the hydrolysis did not occur in these conditions.

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Polymerization of acrylamide in aqueous solution by the action of ultrasonic (US) irradiation (420kc/s) was investigated and was compared with the reported results of γ-ray induced polymerization of the monomer in aqueous solution. Dependence of polymer yield and molecular weight of the polymer on the irradiation conditions were studied. The polymer yield increases with irradiation time until the yield gets to a saturation value whereas the degree of polymerization decreases with irradiation time. Effect of the temperature on the polymer yield is larger than in the case of radiation induced polymerization, indicating differences in the primary proccesses for γ-ray and US-irradiations. The initiating species have been examined by means of the scavenger method. On the basis of decomposition mechanism of water by US-irradiation, the polymerization is thought to be initiated by the reaction of acrylamide during cavitation with hydroxyl radicals and/or other active intermediates such as excited water molecules which eventually produce hydrogen peroxide. The contribution of hydrogen atoms or solvated electrons after diffused out from the site of cavitation to the initiation step is unlikely since the addition of argentous perchlorate which is non-volatile and is known as a selective scavenger for hydrogen atoms are solvated electrons, does not affect the polymer yield. Other vinyl compounds were also examined for their polymerizability in aqueous solutions under US field. Methacrylamide and methacrylic acid were polymerized well, but methyl methacrylate. acrylonitrile and vinylpyridine were almost inert to US irradiation.

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To investigate the initiation reaction in the polymerization of methyl methacrylate (MMA) by diethyl aluminum diphenylamide (Et₂AlNPh₂) at low temperature, the reaction of MMA and equimolar amount of Et₂AlNPh₂ was carried out in toluene at -50°C. From the reaction mixture a crystalline cyclic trimer, dimethyl 2, 4, 6-trimethyl -2-diphenylaminomethylcyclohexanone-4, 6-dicarboxylate, was obtained. The reaction between MMA and LiNPh₂ gave the same compound A (mp 99°C), and the reaction of LiNPh2 and methyl β-bromeisobutyrate also gave a cyclic trimer B (mp 141°C) of MMA but a stereo-isomer of A From the IR spectra A and B were proposed to have configurations lld (or ddl) and lld (or ddl), respectively. The reaction of MMA and Et₂AlSBu also gave a cyclic trimer containing BuS- group. From these results it was concluded that the polymerizations of MMA by Et₂AlNPh₂and Et₂AlSBu at low temperature are initiated by Ph₂N- and BuSanions, respectively, and proceed with anionic mechanism.
The polymerizations of MMA by Et₂AlNPh₂ were carried out at low temperature in various solvents, such as toluene, n-hexane, diethyl ether, tetrahydrofuran. All the polymers obtained were syndiotactic independently of the solvent used. MMA was also polymerized by Et₂AlN (CH₃) Ph, EtAl (NPh₂) ₂and Et₂AlSBu to give the syndiotactic polymer. The polymer obtained by EtAl (NPh₂) ₂ or Et₂AlNPh₂ in toluene at -78°C was highly syndiotactic and was crystallized by the treatment with 4-heptanone. The dimeric form of the catalyst at the growing chain end was postulated to account for the stereoregulation in the polymerization.

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The dynamic mechanical properties of poly (4-methyl-1-pentene) fractions were studied in relation to the fine structural heterogeneity which was estimated with various physicochemical properties. Some samples prepared by Ziegler-Natta catalytic system were fractionated by successive solvent extraction method with a series of solvents at their boiling points.
It was found that the stereoregularity of the fractions increased with higher extracting temperature, while the molecular weight of the fractions with higher stereoregularity remained approximately unaltered. The stereoregularity of the fractions was evaluated by making use of Miller's equation and it was concluded that the polymer could be regarded as a block copolymer composed of isotactic and atactic sequences.
By the measurements of the temperature dependence of dynamic mechanical properties in the temperature range from 0°C to 20°C, at the frequency of 110c/s, it was found that the peak temperatures in tan δ corresponding to the primary absorption for the undrawn slowly cooled crystalline films shifted to the lower temperatures as the degree of crystallinity of the samples increased, while for the drawn samples the primary absorption temperatures manifested in the maximum of the loss modulus shifted to the higher temperatures with increase of the stereoregularity. Furthermore, the effect of thermal history during the preparation of the films on the viscoelastic properties, and the secondary dispertion of E″ for samples probably caused by the crystalline phase were also investigated in relation to the stereoregularity. The characteristic bulk of this polymer indicated by the various experimental results may be interpreted in relation to the anomalous feature of the packing density of the polymer chains in the amorphous phase.

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Copolymerizations of N- (4-substituted phenyl) maleimide [N- (4-RP) MI] (M₂) with styrene (M₁) or methyl methacrylate (M₁) by a radical initiator were carried out, and the effects of substituents of N- (4-RP) MI on the copolymerization reaction were investigated. For the relative reactivities of N- (4-RP) MI toward polystyryl radical, no reasonable order was obtained for all substituents. And all of the resulted copolymers were observed to consist of 1: 1 molar composition of N- (4-RP) MI and styrene, independent of themonomer feed ratios in all copolymerization systems. This result will be understood by the fact that in this reaction system the electrostatic interaction between two monomers, styrene and maleimide derivative, is much stronger than the effects by 4-substituent in N- (4-RP) MI.
The differences in relative reactivities (1/r₁) of N- (4-RP) MI toward polymethyl methacrylate radical were clearly found. Linear relationships between the log (1/r₁) and Hammett's σ values, and also between the e₂ values and σ were found.
where ρ=-0.18
Futhermore, we have found a linear relationship between the log 1/r₂ and the σ values. This agrees with previous results in the copolymerization system of N- (4-RP) MI (M₂) with vinyl acetate (M₁). These results might indicate that the radical reactivities of N- (4-RP) MI depend on the polar characters of the 4-substituents.

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Syntheses and radical polymerizations qf β-methylthio-ethyl methacrylate, 2-methylsufinylethyl methacrylate and 2-methyl-sulfonyl-ethyl methacrylate were carried out. The properties of the polymers obtained were investigated. It was found that the poly- (2-methylsulfinyl-ethyl) methacrylate and poly- (2-methylsulfonyl-ethyl) methacrylate obtained were soluble in water.

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