Polymer blends were prepared from epoxy resin and bismaleimide (BMI), which form polymer networks, via different reaction mechanisms. Influences of concentration of BMI on dynamic mechanical, tensile, and thermal degradation properties were examined for these blends. The rubbery modulus and primary dispersion temperature (T_α) considerably increased with increasing BMI component. The modulus behavior in the rubbery state followed Budiansky's equation and suggested the formation of Interpenetrating Polymer Networks (IPN). T_α followed the T_g prediction for copolymers, indicating a profound molecular mixing between the two components. The activation energy (ΔE) for the primary dispersion was determined from the temperature dependence of shift factor. Increase in ΔE with BMI component indicated that the segmental motion became more restricted. The effects of IPN formation brought about tensile strengths at high temperature which were considerably larger than those of the component networks at 25-50 wt% of BMI and also improved the thermal resistance.

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Mixtures of polypropylene (PP), maleic anhydride (MAH), and peroxide were melt-mixed with a screw extruder. The reaction and the adhesion of the modified PP to saponified ethylene-vinyl acetate copolymer (EVOH) were studied. Although modified PPs made from homo or random PPs do not adhere to EVOH at all, ones made from block PPs show good adhesion. However, even in this case, the reproducibility is poor and the adhesion gradually deteriorates in ambient atmosphere. Unreacted MAH can be easily removed from modified PP by heat treatment above 100°C; good adhesion to EVOH is attained even when homo or random PPs are used.

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There exists much unreacted maleic anhydride (MAH) in modified polypropylenes (PP) which have been made by melt-mixing mixtures of PP, MAH, and peroxide (PO) with a screw extruder. This unreacted material hampers the adhesion of the modified PP to polar materials. In the method of removal of unreacted MAH by heat treatment, the effects of kind of base PP, content of ethylene-butene-1 random copolymer (EBR), and concentrations of MAH and PO on the adhesion to saponified ethylene-vinyl acetate copolymer were studied. (1) With increasing EBR content, the graft efficiency increases and the adhesion improves. (2) The adhesion is poor if the ratio of MAH concentration to PO concentration is too low or too high; an optimum ratio exists. (3) The adhesion is improved by the removal of unreacted MAH by heat treatment. The heat treatment has another good effect on adhesion beside removal of unreactd MAH.

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Structure and mechanical properties of injection molded sheets of blends consisting of a liquid crystalline copolyester (LCP) and a polycarbonate (PC) were investigated by differential scanning calorimetry, X-ray diffraction, optical microscopy, and flexural test. All LCP/PC blends investigated were two-phase systems. Neat LCP and the blend sheets had skin and core layered structure. Crystallinity of the LCP component in the blend sheets was lower than that in neat LCP, and lower in the core layer than in the skin layer. The LCP component had an oriented structure only in the skin layer. Flexural modulus of the blends increased with increasing LCP component. Mechanical anisotropy for the blend sheets was ascribed to the oriented structure of LCP in the skin layer.

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To elucidate the interfacial interaction between the encapsulating polymer and the inorganic powders, the molecular aggregation of the encapsulating polymer was clarified by the experimental results of the thermal behavior, density, infrared spectrum, and molecular weight distribution. Comparison of the thermal properties of TiO₂ encapsulating poly- (methyl methacrylate) and polystyrene with those of the TiO₂ dispersion polymer showed that the encapsulating polymer has two thermal relaxation regions. In addition, the experimental results of GPC, density, and infrared spectrum indicated that the encapsulating polymer has a molecular structure with high density, high molecular weight, and more tacticity.

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Water-soluble graft copolymers (gMS) having the hydrophobic poly (methyl methacrylate) branches with p-styrenesulfonic acid were prepared by macromonomer method. It can be used as an adhesive between tooth and the dental composite resins. In order to discuss the structure of the gMS in the water, the surface tension measurements and the fluorometric measurements with hydrophobic probe were carried out on the aqueous gMS solution. It was found that the gMS formed the micelle structure with a stable hydrophobic domain in the water. The ground bovine tooth enamel surfaces were applied with 3 wt% of the aqueous gMS solution, washed with water, and then characterized by X-ray photoelectron spectroscopy (XPS) and measured the tensile bond strength of the dental resin. The XPS analysis showed that the gMS did not remove from the surface by washing. The tensile bond strength of the dental resin to tooth enamel treated with the gMS solution was higher than the surface with the corresponding random copolymers.

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In this study, we investigated the development of morphology during injection molding and the relationships between molding condition and morphology. Two types of spiral flow: “closed spiral flow” and “open spiral flow” were used in this study. The moldings with closed spiral flow pass through filling, packing and cooling stage, and the moldings with open spiral flow pass through only filling and cooling stage. The morphology and cavity pressure during molding of the two spiral flows were examined in order to establish the development of morphology. The molding condition was changed by cylinder temperature, mold temperature, and injection speed. The relationship between molding condition and variation of morphology was investigated. Three types of morphology were observed: a skin layer, a “microcrystalline layer”, and a spherulitic core. A transcrystal was observed at the end of the moldings and at low flow rates. The skin layer become thickr when the cylinder temperature and mold temperature were low. The extension of microcrystalline layer greatly depends on the flow time. Effects of the cylinder temperature, mold temperature, and injection pressure on crystallite sizes of spherulite cores were small.

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Polymerization of vinyl monomers occurred in the solid phase in a low-pressure cold plasma of argon generated by radio-frequency discharges, i. e., in-source plasma polymerization. The polyacrylamide obtained in the solid-state was insoluble due to the presence of imide groups formed by the elimination of ammonia. Solid-state copolymerization of a binary mixture of a solid monomer and acrylamide (AAm) was also discussed. The phase equilibrium diagram of the methacrylamide-AAm binary system, determined by DSC measurement, shows a eutectic mixture at 90 mol% AAm with a melting point of about 77°C and the formation of solid solutions at the AAm content under 50 mol%. In the solid phase, the rate of polymerization was the highest at the eutectic composition. Prolonged plasma irradiation accelerated the rate only for the mixtures with high AAm content, but at low AAm content, inhibition was observed. From these phenomena, we concluded that an increase in local temperature by the Joule heat due to a dielectric current resulted in the micro-melting of crystals, leading to the rupture of the AAm crystal lattices followed by simultaneous solid-state polymerization.

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Direct aromatic fluoroalkylation of polyimide, 6FDA-BAPF [_??_], was found to proceed by use of bis (fluoroalkanoyl) peroxides [ (R_FCO₂) ₂, R_F=C₃F₇, C₆F₁₃, C₇F₁₅, (CF₂) ₆H] under very mild conditions. The reduction in molecular weight of fluoroalkylated 6FDA-BAPF [6FDA-BAPF-R_F] indicated that the imide groups in the polymer were hydrolyzed with fluoroalkanoic acids which are produced as the by-products of the fluoroalkylation. Furthermore, it was clarified that the T_g value of 6FDA-BAPF-R_F was decreased, whereas the dielectric constant of 6FDA-BAPF-R_F increased by the fluoroalkylation.

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The temperature dependences of ionic conductivity (σ_i) and the dynamic viscoelasticity of poly (ether-urethane) hydrogel (PEUG) were studied. The flection point on the Arrhenius plot of σ_i and the maximum of loss modulus (E'') on the E''-temperature curve were found at almost the same temperature, which corresponds to the phase transition temperature (T_p) of PEUG. The apparent activation energy in the temperature region above T_p was smaller than that in the lower temperature region. In the higher region, the water content in PEUG controlled ionic conduction, and in the lower region, unfrozen water binding the gel molecules controlled it. The T_p of dry PEUG was higher than that of wet PEUG, because dry PEUG contained only bound water, making the structure of PEUG more regid. These results indicate that the ionic conduction of PEUG strongly depends on the molecular motion, while the migration of the water and/or electrolyte into the gel immersed in solution depends on the presence and kind of cations in the solution. The flection point shifted to a much higher temperature around 110°C when the gel absorbed CaCl₂, and a broad peak of E'' was observed at a temperature of ca. 150°C

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Heterogeneous catalytic hydroxylation of allyl chlorides such as 1-chloro-2-propene, 1-chloro-2-butene and cinnamyl chloride was carried out with ascorbic acid and poly (methyl methacrylate) (PMMA) -supported copper (I) as a polymeric catalyst in pH 4.0 under an argon atmosphere at 30°C, and the turnover values were about 50 times higher than that in the absence of the polymeric support. Acylation of the allyl chlorides with the same catalytic system proceeded in an acetic acid buffer solution efficiently as in the hydroxylation. The hydroxylation reaction in this system was investigated under varying reaction conditions to discuss the effects of aqueous solvent ratios, substrates, ligands, and addition of sodium chloride. The catalytic system showed very high activity as compared with that in the absence of the polymeric support. This was explained in term of an increase in the concentration of reaction substrate by hydrophobic micro atmosphere on the surface of the PMMA support and also of the π-allyl copper chloride intermediate formation.

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In order to improve the mechanical properties of nylon 6 fibers, the high-temperature zone-drawing (HT-ZD) was applied. This HT-ZD method is intended to help unfold lamellae and stretch molecular chains. In the present study, the HT-ZD method was carried out over the drawing temperature range from 190°C to 215°C, close to the melting point of 220°C. The draw ratio, birefringence, crystallinity, amorphous orientation factor and Young's modulus for the HT-ZD fibers increased with increasing the drawing temperature up to 210°C. The HT-ZD fiber zone-drawn at 210°C has a draw ratio of 5.3, birefringence of 56.3×10^-3, crystallinity of 51%, amorphous orientation factor of 0.57 and Young's modulus value of 5.9 GPa. However, the bireringence, amorphous orientation factor and Young's modulus of the fibers zone-drawn above 210°C decreased drastically with increasing the drawing temperature. The HT-ZD fiber zone-drawn at 215°C has a birefringence of 7×10^-3, a crystallinity of 38%, an amorphous orientation factor of about zero and Young's modulus value of 0.9 GPa. These values are the same as the values of the original fiber. Consequently, the most suitable conditions of first HT-ZD were found to be a drawing temperature of 210°C and an applied tension of 2 kg/mm². To improve the mechanical properties further, the HT-ZD was repeated 3 times at the constant drawing temperature of 210°C, by increasing the applied tension. The mechanical properties were improved with such processing: the fiber zone-drawn 3 times has a Young's modulus of 7.4 GPa and a dynamic modulus of 12 GPa.

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