Some novel polyazomethines and poly (azomethine-amide) s which contain repeated pairs of disiloxane and pyridine ring in their backbones were synthesized. Their performance for an oxygen permselective material was evaluated. The addition of 1, 5-dichlorohexamethyltrisiloxane to the polyazomethine gave good membrane-forming ability. Such a modified membrane showed an excellent oxygen permeability coefficient (P_O2=1.52×10^-8 cc (STP) ·cm/cm²·s·cmHg). Annealing at 70°C was also effective for improving the membrane-forming ability of the polyazomethines. Poly (azomethine-amide) s had self-supporting property and exhibited much higher oxygen separation factors (P_O2/P_N2=4.39) than those of corresponding polyazomethines (2.96). The polyazomethine having trisiloxane instead of disiloxane and the poly (azomethine-amide) modified by 1, 5-dichlorohexamethyltrisiloxane showed relatively good performance: α≅3.0 and P_O2>5×10^-9. Higher P_O2 values of polyazomethines than those of poly (azomethine-amide) s were attributed to the nature of azomethine bonds, which did not suppress the flexibility of siloxane chains as much as amide bonds did. The water absorption property caused by the existence of pyridine ring enhanced the α and membrane-forming ability of the polyazomethines.

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A series of polyblends, consisting of 90 parts of poly (ε-amino caproic acid) (Ny6) and 10 parts of either poly- (methyl methacrylate) (PMMA), poly (methyl methacrylate-ran-acrylamide) (CPMA), or poly (methyl methacrylate-ran-N, N-dimethyl acrylamide) (CPMD) were prepared in a laboratory kneader and then cast into thin films of ca. 200 μm thick by using a hot press. Rectangular specimens 70 mm long and 4 mm wide, cut out from the films, were allowed to stand in various aeous buffer solutions ranging in pH from 1.68 to 10 for various predetermined periods of time at 40, 60, or 80°C. The changes in intrinsic viscosity ([η]), tenacity, and microstructure of the specimens were evaluated as functions of temperature and pH of the buffer solutions, as well as the time immersed. These results elucidate the role of methyl methacrylate in the minor component on the degradation of Ny6 major component. After the films were immersed in the buffer solution of pH 7 at 60°C for 60 days, the [η] of blend films containing 10 wt% of PMMA decreased to three-fifths of that of the initial untreated one. In acidic solutions, the [η] of the film with the same blend composition decreased much more repidly than in the solution of pH 7. In addition, the film degraded even in basic solution: The [η] of PMMA/Ny6 film stored at 60°C in the buffer solution of pH 10 for 60 days was around two-thirds of that of the initial one, while no significant change was found for Ny6 film treated under the same conditions. The most significant decrease in the [η] was found for both CPMA/Ny6 and CPMD/Ny6 films: The [η] s of these films immersed for 60 days in pH7 solution at 60°C were around two-fifths of that of the initial one. A similar decrease was recognized in the mechanical properties of the blend films. These results suggest that the hydrolysis of Ny6 is facilitated by the carboxylic acids generated in the cocomponents: PMMA, CPMA, and CPMD.

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Core-shell polymer particles with cores of poly (butyl acrylate) and shells of poly (methyl methacrylate) (PMMA) were prepared by emulsion polymerization and characterized by viscoelasticity and thermogravimetry. When allyl methacrylate (AMA) or butyleneglycol diacrylate (BGA) was copolymerized in the core, AMA is more effective than BGA both in crosslinking of the core and graftlinking of the shell onto the core, but is more apt to cause thermal degradation than BGA. With increasing crosslinking degree, the tan δ peak which shows the core transition shifted to lower temperature and became smaller. Similarly, with increasing graftlinking amount, the tan δ peak which shows the shell transition shifted to lower temperature and became smaller. Heating measurement by Flow Tester showed that, with increasing crosslinking degree and graftlinking amount, temperature to initiate flow became higher. The strand from a die was first smooth, then it became like shark skin with die swell, eventually became smooth again, due to strain and stress history.

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Alcoholic hydroxyl groups were introduced into poly (silsesquioxane) [PPSQ] as chain-terminating residues, and the resulting HO-telechelic PPSQ's (HO-PPSQ's) were reacted with propylene glycol (PG) and m-xylylene diisocyanate (XDI) to yield a block copolymer composed of PPSQ and polyurethane repeating units. PPSQ was obtained by the hydrolysis of phenyltrichlorosilane and subsequent condensation reaction. Fractionated portion of PPSQ with M_n=5000 was converted to HO-PPSQ by the end-capping reaction with phenyldichlorosilane followed by the hydrosilylation with allyl alcohol. The mixture of HO-PPSQ and PG was further reacted with XDI to result the targeting (PPSQ-block-urethane) copolymer of M_n-11500. In the IR spectrum of the block copolymer, absorption bands of PPSQ and those assignable to urethane linkages of PG/XDI repeating units were distinguished. The results of DSC measurement also indicated that the products were not mere mixtures but the PPSQ chains were introduced by covalent bonding into the urethane block copolymer backbone.

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In order to produce cement concrete with high fluidity and high quality, cement dispersing agents comprising water soluble polymer have been examined. To find an effective method of molecular weight control for attaining high cement-dispersing ability, polymerization of sodium methallylsulfonate (SMS) was investigated in aqueous solution using ammonium persulfate. The polymerization rate was very slow, and it was found that SMS underwent considerable degradative chain transfer. The copolymerization of sodium methacrylate, sodium ω-methoxyoligo (oxyethylene) -methacrylate (oxyethylene unit=9) and methyl acrylate with SMS was carried out in aqueous solution. In the presence of SMS, the reaction progressed without gelation, and the copolymer having a suitable molecular weight was obtained. These results indicate that SMS is useful as molecular weight control agent for radical copolymerization in aqueous solution.

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An aliphatic polyamide, nylon 6 (T_m=215°C, T_g=48°C), was found to be miscible with an aromatic polyamide, [CO (CH₂) ₄CONH-CH₂-_??_-CH₂-NH] _n (MXD6; T_m=233°C, T_g=75°C), and crystallization from a single phase melt was studied by polarized light microscopy, light scattering, and wide angle X-ray diffraction. The crystallization did not yield co-crystals. At a high crystallization temperature (T_c=200°C) near the melting points, MXD6 cryatallized first and then nylon 6 followed. At a low T_c, close to T_g, the constituent polymers simultaneously crystallized, suggesting the diffusion-controlled kinetics.

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Toughening of Poly (butylene terephthalate) (PBT) by core-shell polymer particles (CSP) was investigated. Two-layered CSP, which consisted of crosslinked poly (butyl acrylate) core (BAC) and methyl methacrylate copolymer shell (MAS) containing glycidyl methacrylate (GMA) units, aggregated in PBT at blending and showed lower toughening effect than ones without GMA. Three-layered CSP, which consisted of BAC, a middle layer containing GMA units and MAS without GMA, dispersed well in PBT and gave PBT with improved toughness. The three-layered CSP of 0.3μm showed maximal toughening, when the thickness of the shell was 5-10 nm and the middle layer was one weight % (per CSP) of GMA homopolymer. This study taught us that the best toughening effect is obtained if CSP disperses as fine particles which form in emulsion polymerization. For this purpose, chemical bonds between CSP and PBT are essential to form grafted polymers. However, it seems that there is a optimal GMA quantity, since the chemical bonds lead to brittleness at the same time, due to lowering of deformation ability of PBT matrix at the interface.

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Spherulitic morphology and phase transition of poly [bis (3, 4-dimethylphenoxy) phosphazene] have been studied by optical microscopy, depolarized light-intensity measurements, DSC and X-ray diffraction. When the thin film of the polymer in its mesomorphic state was cooled down at 5°C/min to room temperature, several larger spherulites (B-type) appeared in the first stage, followed by development of a number of smaller spherulites (A-type). When the sample was heated subsequently, the A-type spherulites and B-type spherulites disappeared at 96°C and 110°C, respectively. These transition temperatures coincided with two DSC endothermic peaks. The extinction in the powder X-ray diffraction patterns of the spherulitic films indicated that thermodynamically less-stable α-type form (orthorhombic, primitive lattice) melted out in the vicinity of 100°C, but the β-type form (orthorhombic, base-centered lattice) remained. The A-type spherulites and B-type spherulites were composed of α-type crystals and β-type crystals, respectively.

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A soluble and an insoluble cellulose IV (Cell IV) in aq. sodium hydroxide (NaOH) were obtained from Cell I and Cell II. The solubility of the Cell IV occurred only in ca. 10 wt% aq. NaOH solution at room temperature. An attempt was made to explain the dissolving behavior of Cell IV in ca. 10 wt% aq. NaOH solution in terms of the micro-structure of cellulose. The effects of trivial differences of micro-structure between the soluble and insoluble Cell IV were studied by CP/MAS ¹³C NMR, WAXS, SAXS, and IR. The crystalline structure fraction of the soluble cellulose showed lower strength of intermolecular hydrogen bond and stronger strain of the micro-structure in comparison with that of the insoluble cellulose. The solubility proved to be governed by the decrease of lattice energy in the crystalline structure caused by the break-down of intermolecular hydrogen bonds at ca. 10 wt% NaOH solution which has the greatest capability to swell toward cellulose.

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Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) in contact with dilute ammonia aqueous solution was endowed with surface wettability by excimer laser irradiation. ArF-laser was more effective than KrF for the surface modification. The water contact angle of the PFA film decreased from 106° to 31°by ArF-laser irradiation with 203 J cm-2. X-ray photoelectron spectroscopy (XPS) spectra indicated loss of fluorine atoms and introduction of nitrogen and oxygen atoms on the PFA surface, induced by a photochemical reaction. The atomic ratios estimated by XPS measurements were closely related to the contact angles with water. From the angular dependence of the F/C atomic ratio of an irradiated PFA film, the thickness of the modified layer was estimated to be 1.5-7.0 nm. No morphological change in the modified PFA surface was observed with a scanning electron microscope (SEM).

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