This development is related to the method of the industrial production of high molecular weight poly-L-lactate having the applicable properties as commodity plastics by use of sugars which are derived from renewable resources. To realize the effect of drawing orientation of films and fibers, high cristallinity of the poly-L-lactate is required. In other words, L-lactic acid preparation having high optical purity must be used as the raw material to produce such high crystal poly-L-lactate. Further, the price of the raw material should be reasonable one to make the price of such poly-L-lactate reasonable. For this purpose, we have developed a technology to produce L-lactic acid preparation of which optical purity is 99.0% by a strain of Bacillus species which has low auxotrophic characteristic. For the industrial production of poly-L-lactate, LL-dilactide was produced from the pre-polymers of low molecular weight poly-L-lactate through the intramolecular transesterification. In the preparation of the pre-polymers, polycondensation takes place where the linear mono-, di-, and trimer of lactic acid are totally refluxed so that the yield of LL-dilactide can be improved, then the temperature of the reactor is raised up in three steps, 135, 150, 160 °C to prevent the racemization of L-lactic acid. The high purity of LL-dilactide is also required to produce high molecular weight poly-L-lactate. The melting crystallization method without a solvent was developed for the purification of LL-dilactide after consideration of lowering the load on the environment. Among various intramolecular transesterification catalysts which we have examined, tin(II) 2-ethylhexanoate showed highest activity and obtained high optical purity LL-dilactide. Ring-opening polymerization of LL-dilactide was continuously took place without a solvent resulting in the production of high molecular weight poly-L-lactate of which weight-average molecular weight is 180000 to 200000. In addition, the properties of poly-L-lactate and the behavior of its biodegradation in a compost were revealed in this work.

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The hydrocarbons emitted just after engine-start (cold-start HCs) cannot be decomposed by a conventional three-way-catalyst (TWC). This paper describes a cold-start HCs removal system that combines a three-way-catalyst with an HCs adsorbent (an HC-adsorption type TWC). The adsorbent is required not only to have high adsorption capacity to HCs, but also to hold the HCs until the TWC reaches its active temperature region. To meet this requirement, the geometrical relation between the adsorbent and TWC was important besides their respective properties. It was found that the multilayered structure of TWC/adsorbent/honeycomb support was most effective in promoting earlier TWC light-off. As for the adsorbent, the zeolite having two kinds of pore sizes (5.5–6.5 Å and 7.5–8.5 Å) was found to be supperior to the zeolites of a single pore size in adsorbing HCs of a wide range in carbon number. As for the TWC, the palladium-based supported catalyst loaded with cerium oxide was most effective in decomposing the HCs desorbed from the adsorbent. It was also found that the geometric surface area of honeycomb affected the HCs holding characteristics of the adsorbent and therefore the HCs conversion efficiency of the whole system. The HC-adsorption type TWC thus improved proved promoting performances for the removal of cold-start HCs.

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Various ZSM-5 type zeolites containing alkaline earth metals with SiO₂/Al₂O₃ ratio 160 were synthesized by varing the OH⁻/SiO₂ ratio in the synthesis mixture. The crystal shape, acidity, steaming durabilities and catalytic properties for the alkylation of toluene with methanol were investigated.
Pyridine TPD showed that the total amount of acid sites is equal to the amount of Al in H-ZSM-5 structure regardless of containing alkaline earth metals. H-ZSM-5 containing alkaline earth metals had the same amount of total acid sites, however it had larger crystal size and larger amount of weak acid sites than H-ZSM-5 without alkaline earth metals. H-ZSM-5 containing alkaline earth metals had larger total amount of acid sites, especially weak acid sites after steaming treatment at 973 K than H-ZSM-5 without alkaline earth metals.
H-ZSM-5 containing alkaline earth metals had better catalytic alkylation activities of toluene with methanol. H-ZSM-5 containing Mg especially showed superior p-xylene selectivity to equilibrium p-xylene selectivity in xylene products.

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Silyl enol ethers were prepared by the reaction of ketones with r-1, t-2, t-5- and r-1, t-2, c-5-isomeric mixture of 1-chloro-2,5-dimethyl-1-phenyl-1-silacyclopentane and 1-alkyl-1-chloro-2,5-diphenyl-1-sila-3-cyclopentene, and their aldol reaction was investigated. The silyl enol ethers were prepared in the presence of triethylamine as base in N,N-dimethylformamide (DMF) or LDA as base in THF. The isomer ratio of the silyl enol ethers implied that retention occurred on Si-substitution in the presence of triethylamine and some inversion occurred on Si-substitution in LDA.
The aldol reaction of these silyl enol ethers were investigated by a reaction with benzaldehyde in the presence of titanium tetrachloride. The aldol products were separated by a column chromatography using silica gel, and obtained as the diastereomers of (R^*, R^*) and (R^*, S^*) forms. The silyl enol ethers from 1-chloro-2,5-dimethyl-1-phenyl-1-silacyclopentane gave more (R^*, R^*) form, and the enol ethers from 1-alkyl-1-chloro-2,5-diphenyl-1-sila-3-cyclopentene gave (R^*, R^*) form selectively.

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Isocyanate-terminated urethane prepolymers (ITUP) and polyurethane elastomers (PUE) have been prepared by the reaction of 4,4′-methylenebis(phenyl) diisocyanate with polyether diols such as α-hydro-ω-hydroxypoly(oxypropylene) (PPG) or α-hydro-ω-hydroxypoly(oxytetramethylene) (PTMG) of various molecular weights. Characterization of the ITUP and the PUE has been carried out by means of differential scanning calorimetry and FTIR spectroscopy. In this article, discussion is made with the interaction development between soft and hard segments on the basis of the evaluated glass-transition temperatures (T_g) and the hydrogen bond interaction among the urethane- and the ether-linkages in molecular chain. The T_g values of ITUP and PUE are considerably high in comparison with those of only the PPG and the PTMG. This implies that the micro-Brownian motion of the oxypropylene and the oxytetramethylene moiety is restricted by the hard segment which contains the urethane linkages having a high activity of the hydrogen bond interaction. Physical crosslinks by the hydrogen bond in the ITUP and PUE are formed between the soft segment and the hard segment and between the hard segment and the hard segment, and the degree of crosslinking is higher with the latter. The PPG-based NH_C–O–C (%) is higher than the PTMG-based one, whereas the PPG-based NH_C=O (%) is lower than the PTMG-based one. Thus rigid hard domain is formed rather with the PTMG-based one.

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We formerly found the novel ring-expansion reaction between 1,3,5-trioxane and ethylene oxide, and identified three novel compounds. Now, we found this type of reaction can be generalized to the ring-expansion reaction between formaldehyde cyclic acetal and ethylene oxide. We, first, confirmed this type of reaction between 1,3-dioxolane and ethylene oxide to form 1,3,6-trioxacyclooctane, 1,3,6,9-tetraoxacycloundecane and 1,3,6,9,12-pentaoxacyclotetradecane. When the initial ethylene oxide concentration is low, the formation of 1,3,6-trioxacyclooctane is predominant and selectivity for the formation of 1,3,6-trioxacyclooctane is nearly 99%. However, with the increase in initial ethylene oxide concentration, the formation of mixed reaction products of 1,3,6-trioxacyclooctane, 1,3,6,9-tetraoxacycloundecane and 1,3,6,9,12-pentaoxacyclotetradecane was observed. Further we confirmed the similar type of ring-expansion reaction between 1,3-dioxacycloheptane and ethylene oxide. From these observations, we concluded the general ring-expansion reaction between formaldehyde cyclic acetal and ethyelne oxide is valid.

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New preparation methods for Ru–Sn/Y zeolites, which catalyze acetic acid (methyl acetate) formation from methanol alone in the gas-solid phase, were investigated. When SnX₂ (X = Cl, Br, I) was impregnated on a [Ru(NH₃)₆]³⁺/Y zeolite from the methanol solution at the ratio of [Sn]/[Ru] = 1.0, the higher activity was obtained with X possessing the higher electronegativity (Cl > Br > I). The larger methyl acetate formation was observed by using a Ru precursor with chloride ligands, [RuCl₂(NH₃)₄]⁺, and SnCl₂. Introducing SnCl₂ as a vapor afforded 14 and 10 times smaller amounts of Sn species on the [Ru(NH₃)₆]³⁺/Y and [RuCl₂(NH₃)₄]⁺/Y, respectively. Nevertheless, the activities were almost the same for the former (3.1% → 2.9%) and somewhat increased for the latter (6.2% → 8.4%), suggesting the formation of more active species.

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