Effects of heating and shearing hysteresis on the flow properties, e. g., the nozzle length correction coefficient ν, Barus effect α and shear stress τ-shear rate γ curve in constant pressure extrusion test, for ABS- and AAS-resin, were investigated. ν, α, and viscosity increased with heating and decreased with kneading. Kneading effect index, which was calculated from the change of the nozzle length correction coefficient, was proposed and its usefulness was investigated. This index increased with the increase in temperature and kneading time.
The change of the above-mentioned properties seems to be due to the change of network density in the rubber particles and graft copolymerization ratio between AS copolymer and rubber.

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A study has been made on the impact tensile behaviors of ethylene-based copolymers (containing about 8.3mol-%methacrylic acid units and about 3.9 mol-%acrylic acid units), and of these partially ionized sodium and zinc salts. Sodium salts have an inclination of a ductile fracture and the fracture energy does not depend on degree of ionization. While, zinc salts show a brittle fracture and the fracture energy decreases with increasing degree of ionization considerably. The molecular relaxation of zinc salts could not be in high response to the impact loading in comparison with that of sodium salts. Swelled sodium salts of ethylene methacrylic acid show lower yield strength and higher elongation than dried sodium salts. It is suggested that the ioncluster is destroyed and the hydrocarbon chain is plastcized by increasing humidities.

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Polyacylthioureas (PATU) were synthesized by the polyaddition of various diamines with isophthaloyldiisothiocyanate prepared in pure crystalline form. The solution polyaddition of aromatic diamines in dimethylacetamide or N-methyl-2-pyrrolidone at room temperature afforded PATU with inherent viscosities of up to 1.39 dl/g almost quantitatively. The interfacial polyaddition of aliphatic diamines in benzene, chlorobenzene, or anisole as the organic solvent afforded PATU of high molecular weight; in this case, the presence of a strong base, such as sodium hydroxide or potassium hydroxide, in the aqueous phase worked to increase the inherent viscosity of the polymer as high as 1.21dl/g. Only low molecular weight PATU were obtained by solution polyaddition of aliphatic diamines or by interfacial polyaddition of aromatic diamines. Thermogravimetric analysis showed that PATU lost their weight by 5% at around 210-220°C in both air and nitrogen.

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Diffusion coefficients of Nylon 12 in melt (D_A) were measured with a microspectrophotometer using a dye-tagging technique. With the increase of diffusion-time, D_A decreased from the value of local diffusion coefficients, D_L, estimated from local viscosity, to that of bulk diffusion coefficients, D_B, estimated from melt viscosity using Bueche's theory. The behavior of D_A is supposed to be qualitatively explained by the mechanical relaxation spectra of polymer chains. At a time scale of shorter diffusion-time, the segmental motion of Nylon 12 chains having shorter relaxation time is dominant. Then the longer the diffusion-time is, the larger scale segmental motion can be observed. At sufficiently longer diffusion-time, the molecular motion having the longest relaxation time will appear, and D_A is supposed to approach the value of D_B or the self-diffusion coefficient of molten Nylon 12. The molecular weight and the temperature dependence of D_A at each diffusion-time were consistent with the molecular mechanism.

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The rheological properties of polypropylene melt filled with various fine particles have been studied. The fillers used were white carbons, magnesium carbonate, calcium carbonate, talc, and glass beads. For polypropylene, the shear viscosity at low shear rate increased and the die swell and the melt fracture were suppressed by the filling. It was inferred that the parison draw-down decreased and the high-speed moldability improved on blow molding. These effects were the most noticeable in the case of the filling with white carbons.

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To confirm the prediction that the blow moldability (BM) of polypropylene is improved by filling with white carbon, the BM was evaluated by use of an actual blow molding machine. By filling with white carbon, the critical resin temperature below which the skin roughness of the parison occurred was reduced, and hence the high-speed moldability was improved. The die swell and the draw-down decreased, and hence the parison approached an ideal form.

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Photo-decomposition of polyurethane prepared from polyester dial and diphenylmethane-p, p′-diisocyanate and its model compounds (N-phenylcarbamates; substituents: methyl (MPC), ethyl (EPC), propyl (PrPC), butyl (BuPC), phenyl (PPC)) was studied by means of electron spin resonance (ESR) and mass spectrometries. Photo-irradiation of the samples at 77K gave mainly singlet ESR spectra, which were deduced to the overlapped signal of the first three radical species among the four radical species generated by the cleavage of N-C and C-O bonds in the urethane groups. The ratio of CO/CO₂ in the gaseous products was affected by the substituents of the samples, namely, ca. 0.4 for MPC, EPC, PrPC, and BuPC; ca. 2 for PPC; ca. 1 for the polyurethane. These results suggest that the photo-decomposition of the polyurethane was initiated by the cleavage of N-C and C-O bonds in the urethane groups.

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Mechanical properties of coating films of water soluble resin pigmented with rutile type titanium dioxide (I) and carbon black (II) werestudied. Vehicles were water soluble acrylic and melamine resin. Stress-strain properties, degree of water absorption, and dynamic viscoelasticity were measur for the films of various pigment volume concentration (C). The adsorption of the vehicles on the pigment surface was studied using gel permeation chromatography. 1) With increasing C. the modulus of elasticity of the films increased, whereas the breaking elongation decreased. The tensile strength and the adhesive strength showed maxima at C=15 and 3-6%, respectively. 2) The interac-tion between the vehicle and I was larger than that between the vehicle and II, and this agrees with the experimental results obtained by the degree of water absorption, T_g, GPC, etc.

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A reactive polystyrene (I) having terminal acyl chloride groups was prepared by radical polymerization of styrene using azobiscyanopentanoyl chloride as an initiator. The presence of terminal acyl chloride groups at the both chain ends of I was estimated by the polycondensation of I with the equimolar amount of 1, 6-hexamethylenediol (II): the polycondensation resulted in the formation of (I-II) _n, type copolymer, where n=3-4. Polycondensation of an equimolar mixture of I and poly (ethylene glycol) (III) gave a (I-III) _n type block copolymer. The copolymer, with n=1.4-1.9, was characterized by IR spectroscopy, turbidimetric titration, osmometry, and GPC. I was also reacted with an excess amount of III (5 kinds with various molecular weights), and III-I-III type block copolymers were obtained. Similarly, a reactive poly (methyl methacrylate) (IV) having terminal acyl chloride groups was prepared and reacted with II to yield a II-IV block copolymer.

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Methyl methacrylate (MMA) and acrylonitrile (AN) block copolymers were prepared by the use of difunctional initiators such as dilithio-acetanilide (DLAC) and dilithio-trans-β-methylcinnamanilide (DLMC). MMA was polymerized first and its “living” end was deactivated, and then AN was added. Homopolymers of MMA and AN were separated from the gross polymer by the successive extractions with benzene and 50-% KSCN aqueous solution. The insoluble polymer showed a solubilization behavior of block copolymer in column fractionation. Ozonolysis of the insoluble polymer obtained with DLMC also suggested that the expected block copolymer was prepared.

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