This paper describes a fundamental study on a foaming cross-linking based on decarboxylative ring-opening oligomerization of five-membered cyclic carbonates. Tetra-n-butylammonium fluoride (TBAF) is an effective initiator for the quantitative decarboxylation in the ring-opening oligomerization of mono-functional five-membered cyclic carbonates. The cooligomerization with epoxides was effective to increase molecular weights. A film of a partially carbonated poly(glycidyl methacrylate) (M_w = 76600, M_n = 23600, and carbonation degree = 29%) containing TBAF was cross-linked by heating, and foamed products insoluble in common organic solvents were obtained.

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Hydro-gel of cross-linked poly (γ-glutanic acid) (γ-PGA) was synthesized by heating a aqueous solution of γ-PGA (pH 4~5.5) in the presence of a small amount of ethylene glycol diglycidyl ether (EGDE) as a cross-linker. Powder samples were obtained by freeze-drying the hydro-gels after neutralization with aqueous sodium bicarbonate solution or without neutralization. Water absorption ratio (weight (g) of absorbed water / weight of dry polymer (g)) of the cross-linked products obtained under the condition of [γ-PGA]/[EGDE]=1/0.05, pH 5.5, at 70 ℃ , for 4 h reached 1200. The obtained powdered samples may be applicable to inhibitors for body organ’s coalescence in surgical sites.

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Naphthol based epoxy resin containing naphthylene linkage (NANAE) was synthesized by the reaction of epichlorohydrin and naphthol oligomer which was obtained by polycondensation reaction of 1-naphthol and bischloromethyl naphthalene. In order to evaluate the effect of naphthalene structure introduced as the linkage moiety of epoxy resin on the thermal properties, naphthol based epoxy resin containing phenylene linkage (NAE) and phenol based one containing phenylene linkage (PAE) were used as references. Although the storage moduli of the cured polymers decreased in order of PAE>NAE>NANAE in the rubbery states, the cured polymer of NANAE gave the highest glass transition temperature of 183.1℃ in the DMA measurement. Coefficients of linear thermal expansion decreased in order of PAE>NAE>NANAE in the glassy states. These results may be attributed to higher content of rigid naphthalene moiety in NANAE.

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Thermo-sensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), was grafted onto carbon microcoils (CMCs), and composite gels of polymer grafted CMCs and PNIPAM were prepared by photo-polymerization. The composite gels were shrunken with increase of temperature as well as normal PNIPAM gel and responded to electromagnetic waves with the presence of contained CMCs which absorb electromagnetic waves and generate heat. The surface temperature of composite gel was reached 43C^owithin 150s and changed its shape with squeezed water.

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Phenolic resin-layered silicate nanocomposites were prepared from solid-type resol and organo-bentonite (MMT) modified with oleylbis (2-hydroxyethyl) methylammonium by hot-roll kneading. At first, the conditions of hot-roll kneading were studied in order to prepare the molding compound which contained resol intercalated into MMT without gelation of resol. As a result, the molding compound was prepared by hot-roll kneading at 90˚C for 15min. Secondly, the curing behavior of the molding compounds was studied. At the initial stage, the melt viscosity of the molding compounds was lowered, and that of the molding compound containing no MMT was slightly lower than others and that of the molding compound containing MMT (5phr) was slightly higher than others. The variation of the melt viscosity of molding compound containing MMT (3phr) was almost same as that containing MMT (4phr). Next, the structure of the composites was investigated by XRD and TEM. It was found that solid-type resol could insert between the layers of MMT and phenolic resin/organo-bentonite nanocomposite could be produced, though there existed a small amount of aggregation of MMT with about 1μm diameter. The properties of these nanocomposites were investigated. It was found that phenolic resin/MMT (3 ～ 4phr) nanocomposites had the best mechanical strength and heat resistance, because of the insertion of phenolic resin between the layers of MMT.

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After a dormant period of nearly half a century, there is a revival of interests in studying small particles adsorbed to gas-liquid interfaces. Colloidal particles with a suitable wettability can be strongly adsorbed to gas-liquid interfaces to work as effective stabilizers for foams. This article mainly presents our studies on (1) the foams stabilized with well-defined polymer particles and (2) the material chemistry using polymer particles adsorbed to gas-liquid interfaces.

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A novel chemical recycling process of phenolic resins has been developed. In this process, cured phenolic resin is completely decomposed in a very short reaction time and recycled resin is recovered in a very high yield by using supercritical or subcritical mixture of water and phenol as a reaction medium. Detailed kinetic analysis clarified the influences of particle size or glass transition temperature of cured phenolic resin and reaction temperature on apparent rate constant of decomposition. The recycled resin was used as alternative feedstock of conventional phenolic novolak and materials with the recycled resin had enough properties for practical use. It was confirmed that properties of the materials with the recycled resin did not decrease when the chemical recycling process was repeated several times. After basic engineering data was obtained with a continuous bench plant, a demonstration plant was constructed. Mass production development has been carried out.

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