Methyl acrylate (MA), acrylic acid (AA) and vinyl acetate (VAc) were polymerized in the presence of polyethylene oxide (PEO), poly (methyl vinyl ether)(PMVE), atactic (a) or isotactic (i) polystyrene (PSt), a-or i-poly (methyl methacrylate)(PMMA), a-or i-poly-2-vinyl pyridine, poly-4-vinyl pyridine or polyvinyl pyrrolidone of 30-50wt%, using radical initiators. These monomers were also polymerized to a high conversion in bulk, and a fraction of the polymers obtained at a final stage of the polymerization was separated. Stereoregularity of poly-MA polymerized in the presence of PSt or PMMA, poly-AA polymerized in the presence of PEO or PMVE, and poly-VAc polymerized in the presence of PEO, PSt or PMMA differed from those of the conventional polymers. The mechanism of stereoregulation of the coexistent polymers was some what discussed.

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The temperature dependence of dynamic viscoelasticities of Nylon 6 and fiber -reinforced Nylon 6 fatigued under planebending were compared with those of unfatigued specimens. Specimens were untreated (equilibriummoisture content at atmospheric humidity), or dried and or heat-treated.
1) In case of Nylon 6, it was found that the fatigue mechanism of the dried specimen was different from thatof the untreated specimen becaue of the difference of temperature depend ence curves of dynamic and lossmoduli.
2) In case of fiber-reinforced Nylon 6, the effect of repeated bending on dynamic viscoelastic properties wasless than tht of Nylon 6, and also the environmental effects, such as temperature and humidity, on their viscoelastic properties were little.
3) A proper heat treatment is effective to decrease the change of dyna mic viscoelasticities caused by fatigue.

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ationic copolymerization of cyclopentadiene (CPD) and o-vinylphenol (OVP) catalyzed by BF₃OEt₂ was investigated at -25°C. The analysis of copolymer composition showed that CPD is more reactive than OVP in toluene and in methylene chloride. The reason could be that CPD is not highly stabilized in the monomer state but is stabilized in the intermediate carbonium ion state. The effect of solvent polarity on the copolymer composition was negligibly small. This fact was interpreted in terms of the similar stability of carbonium ions derived from the two monomers. The degree of polymerization of copolymers was low and copolymerization rate was low. It was considered that OVP participates in transfer and termination reactions as well as in the propaga-tion reaction. The rate of oxidation of the copolymers was much slower than that of poly-CPD.

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The polyelectrolytic behavior of maleic acid-styrene copolymer in aqueous salt solutions was investigated by measurements of potentiometric titration curve, reduced and intrinsic viscosities, and difference spectra in the ultra-violet region. Potentiometric titration curves and viscosity curves sho wed the conformational transition of this copolymer from compact form to loosely coiled form as the degree of ionization increases. On the other hand, the observed difference of spectra seems to indicate that the present conformati onal transition has a relation to hydrophobic bonds between phenyl groups of styrenes in this copolymer. The values of Δ°C, which is the standard free energy chang e of transition from uncharged compact form to hypothetical uncharged loosely coiled form, were calculated from the potentiometric titrati on results in the range of NaCl concentration between 0.0092N and 0.2727N.

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Flow behaviors of a high molecular weight polyethylene were studied by using a parallel plate plastometer and a capillary extrusion rheometer of a constant load. The flow curve at 175°C covering the shear rate range from 3×10^-6 to 10⁸ sec^-1 was obtained. The flow was non-Newtonian even at the shear rate as low as 3×10^-6 sec^-1. The activation energy for flow was 5.9kcal/mole. The flow curve showed a remarkable discontinuity in the shear stress region from 10⁶ to 2.5×10⁶dyne/cm². The zero shear viscosity η₀, the weight average molecular weight and the ratio of weight average molecular weight to number average molecular weight M_w/M_n were estimated by using relations reported in literatures. The results were as follows:η₀(175°C)=10¹⁰ poises, M_w, =2.5×10¹⁰, and M_w/M_n=18.6.

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The contributions of the various glycol components on the tensile properties of the unsaturated polyester resins were studied. Various unsaturated polyesters were prepared from maleic anhydride, adipic acid, ethylene glycol, dipropylene glycol and 1, 3-butanediol. These polyesters were mixed with styrene monomer of 60 and 70 weight%. The tensile properties were measured on the castings prepared from each mixture over the ra nge from room temperature to 120°C. The results are discussed and it becomes clear that the experimental equations previously proposed hold to these formulations.

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The polymerization and copolymerization of 2 -viny1-4, 4-dimethy1-5, 6-dihydro-4H-1, 3-thiazine (VHT) and 2-viny1-4, 4, 6-trimethy1-5, 6-dihydro-4H-1, 3-oxazine (VHO) were studied. It was found that VHT and VHO could homo- and copolymerize with styrene (M₂) and methyl methacrylate (M'₂), respectively, in benzene solution at 60°C using azobisisobutyronitrile as an initiator. The monomer reactivity ratios were obtained as follows:
r₁=0.30, r₂=1.52
r₁=0.19, r′₂=1.81
On the basis of the data, Q, e values of VHT and VHO were estimated.

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The mechanical degradation of the polymeric chains during drawing process of a fiber was investigated. An average molecular weight was found to decrease due to the mechanical scission of molecules when nylon 6 fibers were drawn. The effects of some external actions on the change of the molecular weight were investigated. Undrawn filaments were obtained by an ordinary melt spinning method and drawn at a deformation rate of the order of 10⁷%/min or 10²%/min. The change of the molecular weight was followed by viscometry.
The decrease of the molecular weight is expressed well as a function of the stress on the filament irrespective of the degree of molecular orientation, draw ratio and deformation rate. A stress relaxation or repetition of loading with a same stress on a sample does not bring about any change of molecular weight.
When a predrawn filament is tested, the molecular weight does not decrease in the extention process which corresponds to the early half of the stress-strain curve of the sample, where the relaxed molecules are supposed to be expanded again and the elastic modulus of the filament becomes the highest. It decreases only in the latter half, where further slipping of the molecules takes place and the elastic modulus of the sample falls to a lower value.

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The mechanism of the scission was investigated. Undrawn nylon 6 filaments having various molecular weights were obtained by melt spinning. They were drawn and the changes of molecular weights and molecular weight distributions were examined. From the results, the following concept was confirmed about the mechanical scission.
Molecules are broken selectively from the longer ones at the smaller stress on the filament and preferably at a bond located near the center of a molecular chain. The limited degree of polymerization (P_L) of the molecules which are broken at a certain stress is constant, irrespective of the average molecular weight of the sample. The number of chains broken in an unit volume (weight) of the filament at a certain stress increases with the increase of the average molecular weight of the undrawn sample.
Above concept suggests that the fiber structure of an ordinarily melt-spun nylon 6 fiber should be that of the fringed micell type, where each molecules are expanded and oriented in the direction of the fiber axe. When fibers are drawn, molecules are oriented and expanded to a higher degree, slipping even in crystalline regions. This process leads to a increase of intermolecular forces directed to the molecular axe and so to the scission of the molecules.

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The effects of metal stearates (Ba, Pb, Cd, and Zn) on the decomposition of polyvinylchloride in powder state was studied. Differential thermal analysis were used for the action of hydrogen chloride that reacted with the stabilizers during thermal degradation of polyvinylchloride.
The dehydrochlorination of polyvinylchloride was found to be enhanced in the presence of these metal stearates, and accompanied with exothermic peaks in the differential thermal analysis. The peak temperatures and shapes varied by used metal soaps. Zn-stearate accelerated thermal degradation of polyvinylchloride and showed more low peak temperature than other metal stearates.
From these results it was concluded that differential thermal analysis is very useful for explaining the mechanism of metal soaps in polyvinylchloride.

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1, 1, 2-Trichloropentadiene (TCP) was polymerized in the presence of 2, 2'-azobisisobutyronitrile (AIBN) at various concentrations at 60°C. The degree of polymerization of the polymer obtained was from 10 to 18 and depends on the concentration of AIBN. The polymerization rate was kinetically treated. It was indicated that, because of small propagation rate constant, the degree of polymerization may be very small.

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