Tensile behavior of several plastic-rubber two-phase polymer systems, such as blends of polyvinyl chloride (PVC) and rubbers with different chemical structure, ABS polymer and high-impact polystyrene, has been measured by an Instron-type tensile tester with strain rate of O.25 to 25min^-1 over a temperature range of-40 to 60°C.
Yield stress (σY) can be reduced by strain rate-temperature reduction law, and the composite curve obtained by shifting (shift factor is aT) is expressed by the following empirical relation, _??_
where K₁ is the yield stress at reduced temperature (a_T=1) when the strain rate (ε) is 1min^-1, and K₂ representing the slope of the composite curve is a material constant independent of temperature and strain rate.
As to elongation to break (εo), a new peak, which is probably caused by a crazing phenomenon, appeared below room temperature, in addition to the peak observed around the glass transition temperature of rigid matrix. The former peak shifted markedly to higher temperature with increase in strain rate.
Apparent activation energy of yielding obtained from temperature dependence of a_T was well correlated with the Charpy impact strength, indicating an important contribution of energy of yielding (crazing) to impact strength.

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In the previous experiment on the model foam with equal spherical cells, we found that the dynamic viscosity coefficient η_p, and the compressive modulus E_p of the isolated foam can be expressed as, η_p=ηmp+η0 (1-p), E_p=E_m {p²+β(p-p²)}, where p is the packing factor of the foam, η_m and E_m the viscosity coefficient and the compressive modulus of the polymer, respectively, and η0, and β are structural factors independent of the foam material.
In order to have more detailed knowledge on the structural factors, measurements were carried out on the dynamic compressive behavior of the model foam with various types of the distribution of cell radii. It was found that η0 was independent not only of the foam material but also of the cell radius and its type of distribution. Since β is proportional to the cell radius, the empirical equation for E_p becomes, E_p=E_m {p²+kr (p-p²)}, where r is the average value of radii of spherical cells and κ a constant independent of the foam material and of types of the distribution of cell radii.
The experimental data for commercial polyethylene foam and polyvinyl chloride foam are in good agreement with the empirical equations cited above. It was found that these equations may provide an excellent guide in the design of foams having desired values of dynamic viscosity coefficient and compressive modulus.

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The emulsion polymerization of isoprene-methyl methacrylate (1: 2 or 1: 1 molar ratio) was studied at 60°C using potassium persufate as an initiator and sodium dodecyl sulfate as a detergent. The results were as follows: 1) With the change of pH of the solution from acidic to aikaline, the particle size increased but the polymer yield decreased. The persulfate was consumed rapidly in an alkaline solution, without the expected increase in the yield.2) Though isoprene was seldom activated to radical by the initiator owing to its insolubility in water, the reactivity of isoprene in the polymer particles swollen with monomer was much larger than that of methylmethacrylate.3) The hydrolysis of methyle methacrylate was minimum (negligible) at pH 6.4-6.6.4) Carboxyl groups per g of polymer in the polymer formed by hydrolysis and measured by infrared absorption was larger than that measured by potentiometric titration method. It means that the latter method could not detect the hydrolysed carboxylate in the inner part of particles because of the shorter titration time (about forty minutes). Titration curves showed gentle slope indicating that carboxylic acid has various dissociation constants; that is, the dissociation constant on the surface of particles may be different from that in the inner part. In fact a dissociation constant evaluated rather definitely from a titration curve, was found to be pK-6 and smaller than that of monomer.5) By bromine addition, polymer was transformed to a compound having γ-lactone ring.6) In paper electrophoresis, a correlation was found between the mobility of the particles and their hydrolysed carboxylate content.

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Copolymerization of 1, 3-cyclohexadiene (1, 3-CHD) with sulfur dioxide was studied. 1, 3-CHD copolymerized with SO₂ without initiator even at-78°C. Copolymers obtained from the heterogeneous copolymerization systems were white powder and soluble in phenols and in SO₂ below about-35°C, on the other hand, copolymers obtained from the homogeneous systems were ivory-like and insoluble in ordinary solvents.
The composition of the copolymers was alternating (1.3-CHD: SO₂=1: 1) and the structural unit consisted of the cyclohexene ring substituted with SO₂ at the 3-and 6-positions.
The initial rate of copolymerization (R_po) showed a maximum value at about-35°C and decreased above this temperature. It was assumed that this dependence of R_po on the temperature was related to the change of miscibility of the components in the copolymerization system and of the solubility of the copolymers at about -35°C. The apparent over-all activation energy of the copolymerization was 4.7 kcal/mole below-40°C. R_po was second order with respect to the initial concentration of 1, 3-CHD and third order with respectto SO₂ at-40°C, but at 0°C, second order with respect to the both components.
The copolymer began to pyrolyze at about 180°C and was also decomposed by aqueous alkali or by liquid ammonia. It was considered from the measurement of X-ray diffraction that polysulfone was partly crystalline.

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The radical copolymerizations of cis-and trans-methyl propenyl ethers (MPE) and 2, 3-dihy dropyran (DHP) with maleic anhydride (MAn) or acrylonitrile (AN, M₁) were carried out at 60°C.
The copolymerization of these monomers with MAn gave alternating copolymers, and the rates of the copolymerization decreased in this order: cis-MPE>trans-MPE>DHP. The formation of charge transfer complexes of those monomers with MAn in solution was observed spectroscopically and is considered to be related to the reactivities.
The reactivities of cis-and trans-MPEs and DHP toward AN radical (1/r₁) were as follows: cis-MPE 0.431-trans-MPE 0.347>DHP 0.143. The similar reactivity of cis- and trans-MPEs was considered to be due to nearly equal free energy of the isomers in the monomer state. DHP monomer is stabilized by the conjugation of the double bond with the lone pair of the oxygen atom, but, the ring structure in the polymer has a strain. This may be related to the low reactivity of DHP.

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The radical terpolymerization of acrylonitrile [M₁], cis-methyl propenyl ether [MPE, M₂] and trans-MPE [M₃] was carried out at 60°C. Since MPEs have negligible rates of selfpropagation, equations for terpolymer composition are simplified. The monomer reactivity ratios were evaluated graphically using residual monomer concentrations asfollows:
γ₁₂=2.72±0.06, γ₁₃=2.66±0.06.
The fact that the monomer ratios of cis-MPE to trans-MPE were constant during the polymerization indicates that the reactivity of cis-MPE toward the acrylonitrile radical is the same as trans-MPE (γ₁₃/γ₁₂= 1.00±0.04). The observation is in good agreement with those of copolymerizations of cis- or trans-MPE with acrylonitrile.

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Cotton linter is immersed in acetic acid aqueous solutions (1: 1 vol.) of sulfamic acid (SA), ammonium sulfamate (AS), hydroxylamine sulfate (HS). The excess imbibitionacid is removed by suction and then the cellulose is acetylated with a mixture of acetic anhydride and diluent at 50-100°C.
Under appropriate conditions, cotton linter impregnated with the catalyst is acetylated smoothly; for example, triacetyl cellulose can be obtained in the acetylation by acetic anhydride at 70°C for 2-5 minutes. The catalytic effectiveness of these compounds is as follows;HS≥SA>AS
The acetylation reaction is accelerated by the addition of the diluents which have only a little affinity to these catalysts, since the dissolution of the catalysts into the acetylating bath is prevented.
Effectiveness of the catalysts and the diluents to obtain the acetate with high degree of polymerization is as follows;HS>SA=AS, CH₂Cl₂+C₂H₅OH>none>C₆H₆≥CH₃COOH.

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Polyvinyl Chloride (PVC)-potassium alkylxanthate blends or PVC containing xanthate group at the side chain formed crosslinked structure with sulfide groups by immersing them in ethylenediamine at 30°C for about 60 min (Equation 1 and 2). The crosslinked PVC having the similar structure was also obtained from PVC-NaSH blends by the similar procedure._??_(1)_??_(2)
The crosslinked PVC was similarly obtained by immersing PVC-polyxanthate blends in ethylenediamine (Equation 3). The structure of the crosslinked PVC thus obtained was the same as that from PVC-polythiol blends by immersing them in ethylenediamine, because the polyxanthate produced the polythiol by the similar procedure.
These crosslinking reactions (1)(2)(3) were also confirmed by the experiments on the model compounds. The crosslinking conditions and the properties of these crosslinked PVC were studied.

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Flow behaviors of isotactic polypropylene melt and it's stress relaxation following after sudden cessation of flow have been studied. Viscosity measurements were performed at 250°C at shear rates ranging from 2.72×10^-2 to 2.08×10 sec^-1 under nitrogen atmosphere by using a cone-and-plate rotating viscometer. Six fractions and a whole polymer having viscosity-average molecular weights M_v ranging from 6.2×10⁴ to 39.6×10⁴ were used. The sample in powder form were molded before use into disks, 4 cm in diameter and 0.04cm thick. It was observed for samples having larger M_v under larger shear rate that shear stress passed through a maximum which was followed by a pronounced decrease to it's steady value. The time necessary for attaining steady state was strongly influenced by both M_v and shear rate. It became clear that in capillary flow of melt the contribution of transient unsteady flow accompanied by the disentanglement of entangled networks to melt viscosity obtained can not be ignorable. The shear rate at which the transition from Newtonian to non-Newtonian flow occurred was inversely proportional to M_v
The slope of double logarithmic plots of zero shear viscosity against M_v, was found to be 3.6, approximately agreeing with the value expected from the theory. Stress relaxation at constant deformation after the rotation had been stopped was found to be non-linear even if the steady flow preceding sudden cessation was Newtonian, leading to conclusions that the phenomenological cause for non-linear stress relaxation is non-Hookian properties of elastic elements in a melt, and that the method for evaluating the recoverable shear strain from the data of end correction factor in capillary flow of the melt is, in principle, inapplicable.

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In order to investigate the fine structure of polyethylene terephthalate (PET), PET fibers which have different mechanical and thermal history have been degraded in a 70% aqueous monoethylamine solution at 30°C. for various timeintervals. Then, on the insoluble fraction during degradation, the changes of weight loss, X-ray crystallinity, viscosity-average molecular weight, long period and amide group content were measured, and melting behavior and morphology were observed.
At the first stage, a rapid weight loss, increases in crystallinity and in amide group content, a steep drop in molecular weight, a decrease in long period and depression in melting point were observed. At the second stage following the first stage, a slow rate of weight loss and essentially constant values of other parameters were observed.
This indicates that rapid initial degration of the noncrystalline portion is followed by slow degradation of the crystalline lamellae at their lateral surfaces.
From the electron microgeaphs of the aminolyzed residue, it was found that undrawn PET fibers consist of lamellae-like structure, while drawn PET fibers consist both of lamellae like structure and fibril-like structure. The interprelation of the thermogram for melting behavior is in accord with the findings from electron microscopical observation.

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Sedimentation measurements were carried out at 115°C, at 60000 rpm with a Hitachi Analytical Ultracentrifuge “UCA-1A” with a titanium rotor. Sharpening and distorting phenomena were observed on the Shlieren optics, and were prevented by improvement of the heating system. Sedimentation coefficients were measured and the degree of long-chain branching was calculated for two branched polyethylenes and one linear polyethylene.

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