The effect of the microtacticity and aggregation on molecular motions within the stated temperature range have been studied. Samples of uniform molecular weight fractions and non fractionated polymer were subjected to a comprehensive characterization in respect of molecular weight, density, crystallinity %, type of crystallite and infrared absorption prior to molecular motion studies.
Techniques employed in the study of molecular motions were dilatometry, differenti al scanning calorimetry (DSC), loss of mechanical modulus with temperature variation, and nuclear magnetic resonance (NMR).
Inferences reached were as follows.
1) Three kinds of transition points T_g1, T_g2 and T_g3 existed within the temperature range studied. Such transition temperatures were detected by dilatometry for both isotactic and atactic polymer.
T_g1 was assigned to a localized mode of molecular motion in the amorphous regions and was quite independent of overall tacticity and crystallinity. However, T_g2 and T_g3 appeared to be strongly influenced by microtacticity.
2) DSC indicated T_g1 and T_g2 values for the atactic polymer to be -60°C to -40°C and -20°C to -5°C respectively.
3) The characteristic nature of specific-volume temperature relationships were readily accounted for by the observations (a) a rapid secondary crystallization of the smectic forms occured above room temperature, (b) this smectic form underwent transition to the monoclinic form over a wide temperature range above 70°C.
4) Peak temperature of viscoelastic dispersion at room temperature fell off with decreasing micro-tacticity and there was a strong concomitant fall in the values of tangents to such peak temperatures. This dispersion could be accounted for as the glass transition due to the chains with lower microtacticity.
5) NMR measurement indicated the occurence of partial motional narrowing at temperatures above -100°C. Such observations were suggestive of the independent existence of smaller “daughter” regions of microtacticity within the main phases. Motional narrowing due to the micro-Brownian movement in the amorphous phases could be initiated at higher temperatures for polymers of higher microtacticity. The NMR spectra of the isotactic polymer underwent no apparent change following heat treatment of the polymer. Change in the fraction ratio of broad to narrow line components were very marked at room temperature even for the sample of annealed polymers in which the crystallinity was constant. Above 50°C, melt grown crystals exihibited only a narrow line component, whilst the major part of the broad line component, was retained for solution grown crystals.

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The nuclear magnetic resonance spectra of polyacrylonitriles prepared under various polymerization conditions were measured in NaCNS-D₂O solution. The methylenic proton resonance could be separated into two triplets: one is due to the protons of the syndiotactic methylene groups and the other is due to the isotactic ones. The tacticity of polyacrylonitrile could be determined by the ratio of the integrated intensities of the two triplets.
Polyacrylonitrile samples prepared with the radical catalysts have the syndiotactic part of approximately 75%, and polyacrylonitriles prepared by the anionic polymerization at low temperature, γ-irradiation in solid state, Mg molecular beam and γ-irradiation on the urea canal complex are more isotactic but have no remarkable stereospecificity.

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In our previous work GPC was compared with the light scattering for fractionated low cis-polybutadiene.
This work used column chromatography for comparison with GPC using the commercial low cis-polybutadiene.
Isobutylacetate and ethylacetate were used respectively as solvent and non-solvent. Temperature gradient (40-22.5°C) was taken for good fractionation.
GPC results obtained by two methods, area and line, were compared with column chromatography and the former was more consistent with column fractination except for higher molecular weight.
The reason of unconsistency in higher molecular weight were that in column chromatography part of higher molecular weight eluted out with lower molecular weight fractions and that there was broad trailing in GPC at higher molecular weight.

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The absorption band at 1378cm^-1 (due to symmetric deformation of methyl-group) has been used most frequently for the quantitative determination of the branching in polyethylene. But, this method has proved not enough to detemine accurately the degree of branching.
Using various model-substances the absorption coefficients of the hand at 1378cm^-1 were obtained as follows:
Methyl-branching: k₁₈₇₈=1.83, R=2.65
(Polymethylene+amorphous Polypropylene)
Ethyl-branching: k₁₈₇₈=1.21, R=1.75
(Polymethylene+amorphous Poly-1-butene)
Butyl-branching: k₁₃₇₈=0.931, R=1.35
(Polymethylene+amorphous Poly-1-hexene)
Terminal-methyl-group (or Long-branching)
k₁₃₇₈=0.691, R=1.00
(Polymethylene+n-Alkane)
where; k₁₃₇₈=absorption coefficient at 1378cm^-1 band,
R=ratio of absorption coefficients.
Therefore, it was shown that 1378cm^-1 band could be used to determine the degree of branching, when there was only one kind of branching.
Methyl-branching was determined by 1155cm^-1 band due to skeletal-vibration of>CH-CH₃
group and the following relation was obtained.
_??_
Ethyl-branching was determined by 762cm^-1 band due to rocking of methylene group and the following relation was obtained.
_??_
Terminal-methyl-group and long-branching were determined by the following equation using the absorbances at 1378cm^-1, 1155cm^-1 and 762cm^-1.
_??_
where; D₁₃₇₈: absorbance at 1378cm^-1 band
D₁₁₅₅: absorbance at 1155cm^-1 band
D₇₆₂: absorbance at 762cm^-1 band
t: tnickness of sample in cm
d: density of sample in g per cm³
n: branches per 1000 carbon atoms
Relationships between the crystallinity and the short chain branching were studied using ethylene-propylene-random-copolymers and ethylene-l-butene-random-copolymers.
As the results, the following experimental equations were obtained.
Methyl-branching:
_??_
Ethyl-branching:
_??_
where; X: crystallinity in %,
M: average molecular weight (×10^-4)
n: branches per 1000 carbon atoms
However, these relations were applied for the following
ranges: 4.0≤M≤10.0, 1.0<n≤10.0.

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The crystallinity of poly-4-methyl-pentene-1 was studied by infra-red spectra, density and X-ray.
We found that D₈₄₉/D₁₁₇₀ is the measure of crystallinity and D₈₄₉/D₁₁₇₀ shows a linear relationship with negative slope against densities, but positive slope against crystallinities obtained by X-ray. Extraporating D₈₄₉/D₁₁₇₀ to zero, the density of amorphous phase was estimated as 0.841, which is well consistent with the result of other methods.
Samples having various crystallinities were used to measure viscoelastic properties, and from the dependence of the values of E′ max and E″ max upon crystallinities the densities of crystalline and amorphous phases were estimated as 0.823 and 0.840, respectively. The values of activation energy of relaxation in the amorphous and crystalline phases were 79 and 26kcal/mol respectively.

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Quantitative analysis of them icrostructure of cis-polybutadiene blended with emulsion polybutadiene was carried out by using the Attenuated Total Reflection Spectrometer (ATR). The angle change of the incidenctoe the surface of cis-polybutadiene was investigated to clarify an optimum angle for detection of cis-, trans-, and vinyl-structures. Apparent concentration of each structure was calculated by using the modified equation of Morero, and was compared to the concentration determined from usual transmission IR method to afford a calibration curve.
As the result, ATR method was found to be suitable for a quantitative analysis of the mirco-structure in polybutadiene or polybutadiene blend. Moreover, it is expectable that this method is able to apply to an analysis of the microstructure in polybutadiene vulcanizaite.

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Cis-trans isomerization and consumption of double bond in cis-polybutadiene during vulcanizaion were analyzed quantitatively by using the Attenuated Total Reflection Spectrometer (ATR). The result shows that cis-structure was isomerized by some curing agents to afford trans-structure. Decreasing amount of the double bond by peroxide was found to be much higher in compaisron with sulfur-accelerator system. Crosslinking efficiency based on the concentration of decomopsed peroxide has attained to about 10. The evidence obtained supports the suggestion that peroxide vulcanization for cis-polybutadiene should proceed by radical transfer reaction to the double bond.

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The effect of polymerization conditions on the structure of the resultant polymer has been studied for n-BuLi and PhMgBr catalyst systems. These catalysts are chosen as Li and Mg compounds exert a strong coordinating power with an amide group. The effect of momomer concentration and degree of conversion on the structure of the polymer obtained with n-BuLi is relatively small. If monomer molecules do not participate in the transition reaction, it is accounted kinetically for the effect of monomer concentration and degree of conversion on the structure of polymer. n-BuLi and PnMgBr produce mainly the transition polymer irrespective of solvent polarity. This result shows that the catalyts which forms a complex with an amide group has a tendency to produce a transition polymer. Using n-BuLi as a catalyst, the polymerization proceeds at low temperature (40°C) and the polymer obtained at 40°C contains a large amount of vinyl polymer unit.

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As an approach to the study of polymerization of internal olefins, olefins were converted into cyclopropane derivatives by means of the carbene reactions, and the polymerizations thereof were studied. The original internal olefins used were of the types, RCH=CHR, R₂C=CHR and R₂C=CR₂, where R was methyl or chlorine.
By using radical initiators, these cyclopropanes neither homopolymerized nor copolymerized with maleic anhydride and with styrene. In the cationic polymerization, low molecular weight polymers were obtained. The structure of these oligomers were examined by NMR and IR spectra. In the case of methyl-substituted cyclopropanes, it was found that the ring-opening polymerization occurred but that the position of the opening seemed to vary with monomers. In the case of chloro-substituted cyclopropanes, dehydrochlorination was observed yielding polymers having cyclopropane rings in the main chain. Anionic catalysts did not work at all.
The thermal isomerization of the monomers was also investigated. Chloro-substituted cyclopropanes were found to isomerize to olefins. Pentachlorocyclopropane isomerized at 200°C to CCl₃CCl=CHCl and the latter in turn decomposed further at 300°C to give hexachlorobenzene.

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The vinyl trimethylsilyl ether (VOSi) was polymerized with cationic catalysts. Poly (VOSi) was easily converted into poly (vinyl alcohol)(PVA) by solvolysis after the polymerization. Based upon the study of the IR spectra of PVA, the PVAs obtained by the polymerization in less polar solvents were found to be rich in isotactic and those obtained with polar solvents were found to be rich in syndiotactic. Effect of polymerization conditions on the stereoregularity of the polymer was studied to find out the optimum condition for the stereoregulation. The highest syndiotacticity was effected by the polymerization at -78°C, using a system VOSi-EtNO₂-SnCl₄ and a monomer concentration of 5-10vol%. The highest isotacticity was produced by the polymerization at -95°C using a system VOSi-Toluene-EtAlCl₂ and a monomer concentration of 5vol%. Hence, it was found that the stereoregularity of the PVA could widely be regulated by using VOSi and by selecting the suitable catalyst and the solvent.
From the comparison of IR spectra of the differently stereoregular PVAs, it was found that the optical density ratio, D₁₄₅₀/D₂₉₃₀, was more suitable as a qualitative measure of the stereoregularity than D₉₁₆/D₈₄₉ in the highly isotactic region.

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In radical copolymerization of methyl acrylate and vinylidene choride by α, α'-azobisisobutylonitrile in benzene at 60°C, the monomer reactivity ratio was determined from unreacted monomer contents by gas chromatography. Thus, the terminated copolymerization mixture was injected directly to gas chromatography. Unreacted monomer contents were determined from relative peak area of gas chromatogram and compositions of the copolymer were calculated. The monomer reactivity ratios of methyl acrylate and vinylidene chloride by this method agreed with that of elementary analytical method of chorine analysis.

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Polymerization of adipaldehyde was investigated under various conditions, as one of the series of the studies on the polymerization of bifunctional monomers.
Polyadipaldehyde obtained by using catalysts such as BF₃·O(C₂H₅)₂ and Al(C₂H₅)₃/H₂O, was partially soluble in usual organic solvents. Since the pendant aldehyde content of this polymer was considerably high (60-70%), it was concluded that cyclopolymerization took place for adipaldehyde but the extent of cyclization was smaller than that in the case of glutaraldehyde or succinaldehyde.
On the other hand, in the copolymerization with chloral by using BF3·O(C₂H₅)₂ catalyst, the copolymer possessed a nearly equimolar composition and almost cyclized adipaldehyde units. This may be ascribed to the effect of trichloromethyl group of chloral.

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The copolymerization of vinyl chloride (M₁) with n-propylvinyl sulfonate (M₂) was studied in toluene solution at 70°C, using azobisisobutyronitrile as a initiator. It was found that the rate of copolymerization increased with the increase of mole fraction of vinyl chloride in the monomer compositions. The monomer reactivity ratios determined at 70°C were as follows:
r1=0.22, r2=0.40
and from these values, Q and e-values for n-propylvinyl sulfonate were calculated as 0.27 and 1.76, respectively. Copolymerization of vinyl chloride with isopropylvinyl sulfonate, and saponification on the copolymer were also examined.

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