Maleimides are useful for improving the heat distortion temperature of resins. However, the economical industrial production method for these monomers has not been established because of the difficulties during the process operations. We have developed a new industrial production process of maleimides based on the proposed reaction model. This process contains following new technologies; (1) the yield of N-phenylmaleimide (PMI) is significantly improved, (2) PMI is directly produced from aniline and maleic anhydride (MAN), (3) 2-anilino-N-phenylsuccinimide (APSI), which is one of the major byproducts, is converted to PMI via N-phenyl-N- (1-phenyl-2, 5-dioxo-3-pyrrolidinyl) maleamic acid (PPMA) by the reaction with MAN at elevated temperature, and (4) PMI is the stabilized by dissolving in acrylonitrile.

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High performance polyoxyphenylene-polyamide alloy was developed by reactive processinng technology. Addition of very small amount of reactive compatibilizer during molten mixing process partially gives a block copolymer composed of polyoxyphenylene and polyamide which plays an important role in the fine dispersion of the polyoxyphenylene in the polyamide matrix. Reactive compatibilizer has carbon-carbon unsaturated bond and acid group, such as maleic anhydride. The block copolymer was quantified by Soxhlet's successive extraction. The structure of the block copolymer was confirmed by IR and DSC. Transmission electron microscopic observation showed that the block copolymer existe d interface between polyoxyphenylene and polyamide.
To improve the impact strength and heat resistance of materials, we have found that the formation of the “sea-island-lake” (polyoxyphenylene-polyamide-elastomer) structure is desirable.

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The diamagnetic susceptibilities of keto and enol tautomers of 2, 4-pentanedione were determined by the Gouy's method. The molar diamagnetic susceptibility of neat 2, 4-pentanedione and mole percent of enol tautomer were found to be -56 x 10^-6 cm³ mol^-1 and 83%, respectively. The molar diamagnetic susceptibilities of keto and enol tautomers of 2, 4-pentanedione were obtained to be -52.4 x 10^-6 and -56.5 x 10^-6 cm³ mol^-1. While the calculated values of enol tautomer were -53.38 x 10^-6 cm³ mol^-1by the Pascal-Pacult-Hoarau's way and -53.55 x 10^-6 cm³ mol^-1 by Harberditzl's way, respectively. The difference between the experimental and the calculated results on enol tautomer was -(3.0 ± 0.7) x 10^-6 cm³ mol^-1. This could be considered as a result of magnetic anisotropy of enol tautomer of 2, 4pentanedione due to the formation of intramolecular hydrogen bond of six-membered ring, giving a weak ring current effect in the presence of magnetic field.

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The oxidation of benzene to phenol with hydrogen peroxide was carried out by using Keggin-type H₃+_nPMo_12-nV_nO₄₀ (n=0-4; abbreviated by PMo_12-nV_n) in a water-benzene biphase system. The hydroxylation reaction proceeded with the decomposition of hydrogen peroxide and a fairly good correlation was observed for the catalytic activity between them. The catalytic activity for the hydroxylation at 65°C changed in the order of PMo₁₀V₂. ≈PMo₉V₃>PMo₈V₄>PMo₁₁V>>PMo₁₂. The maximum yield of phenol for PMo₉V₃ on H2O2-basis was 36%. The slow addition of diluted aqueous hydrogen peroxide resulted in the great increase in the phenol yield and those for PMo₁₀V₂ and PMo₉V₃ were 91-93% on H₂O₂-basis with 100% selectivity to phenol (benzene basis). The yield of phenol reached the maxima. around 45-65°C. When the slow addition of hydrogen peroxide was repeated, the phenol yield increased singnificantly.

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The homogeneous hydrogenation of phenylacetylene homologs catalyzed by [RhH₂(Ph₂N₃) (PPh₃)₂] (dihydridorhodium complex) in dimethyl sulfoxide (DMSO) was studied under hydrogen at 1 atm, 303K. The dihydridorhodium complex in DMSO was active catalyst for the hydrogenation of terminal and internal alkynes to alkenes. It was observed that terminal alkyne could be reduced easily comparing internal alkyne. The hydrogenation of terminal alkyne, e. g. phenylacetylene was closely linear relationship between the rate of hydrogenation and the reaction time and phenylacetylene was selectively reduced to styrene. The apparent overall activation energy of the hydrogenation of phenylacetylene with dihydridorhodium complex was estimated to be 26.3 kJ mol^-1. On the other hand, the initial hydrogenation products of internal alkynes were cis- and trans- alkenes, the former being more than the latter. It was observed that after the yield of cis- alkenes reached maximum, the yield of trans-alkenes increased rapidly accompanied with the decrease of the cis-alkenes.

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Extraction of lanthanoids (Ln: La (III), Ce (III) and Pr (III)) into 1, 2-dichloroethane with 18-Crown6 (18C6) and trichloroacetate (TCA) has been studied with or without diethylenetriaminepentaacetic acid (DTPA) or nitrilotriacetic acid (NTA). The extractability of Ln was decreased in the presence of DTPA or NTA, whereas the selectivity of 18C6 was increased. This is due to the ligands having opposite coordinating trends toward Ln. Judging from the difference in distribution constants, DTPA was more effective than NTA to enhance the selectivity with 18C6.

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Conformational analyses of various 2', 3'-O-alkylidene (or arylmethylene) adenosines were achieved by NMR techniques. They were synthesized from adenosine and each aldehyde in t he presence of zinc chloride and trimethyl orthoformate at room temperature. When saturated aliphatic aldehyde was u sed, cis-isomer was selectively obtained. In the case of other aldehydes having an aromatic ring or a do uble bond, the corresponding cis- and trans-isomers were produced, and both could be isolated by sil ica gel chromatography. The reason is explained by stability of the products.
The effects on 2', 3'-0-substituents were concluded as fo llows: 1) Compared with diastereomers, most cis-isomers occupy the more predominant S-conformation (C^2'-undo) t han their corresponding trans-isomers. The population of the S-conformation increases with decrease of bulkine ss of the substituent and of the polarity of the measuring solvents. 2) These compounds are found to exist mainly in syn-types, and cis-isomers tend to b e more syn-types compared with their trans-isomers. The more the substituent of the cis-isomers is small or the measuring solvent is nonpolar, the more syn-types occupy.

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The oxidation behavior of commercial carbon steel and Cr-Mo steels with Cr content lower than 12% in steam was studied. The oxidation behavior changed with temperature. Below 550°C, the growth of the oxide scale in steam was slow, and no distinct effects of Cr-content on the growth rate were observed. Above 600°C, the extremely thick oxide scale developed on the carbon steel due to the formation of FeO, while the growth rate of the oxide scale formed on Cr-Mo steels changed with the variation of Cr content in the steels. In higher Cr (ca. 12%Cr) containing steels, the belt-shaped Cr containing oxide scale was formed in the inner oxide layer. The diffusion of Fe through the oxide scale was controlled by the amount of Cr in the inner oxide layer. The high concentration of Cr in the inner oxide layer was found to be effective for retarding the growth of the oxide scale.

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The effect of Si content on the oxidation behavior and the oxide scale structure of 2′ 1/4-9 wt% Cr steels in steam was studied.
The oxidation resis tance of Cr-Mo steels in steam was improved with the increase of Si content in steels up to 0.5 wt% Si. The oxidation resistance of 0.5-1.0 wt%Si containing steels was similarly good. This beneficial effect of Si was remarkable at temperature above 600°C.
The growth rate of the oxide scale was reduced presumably due to the Si en richment in the inner Crcontaining spinel-type oxide layer which retarded the ionization and diffusion of Fe.
The regression analysis was carried out on the relationship between the growth o f the oxide scale and the chemical composition of 2′1/4-9 wt%Cr-Mo steels containing less than 0.5 wt%Si. Si was found to be the most beneficial element and about 5.6 times more effective than Cr. The effect of the grain size of steels on the oxidation resistance was also detected.

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Various kinds of Cr-Mo steel tubes are used in superheaters and reheaters of boilers. The troubles related to the spalling of the oxide scale formed on Cr-Mo steels in steam had been reported in the U. S. A. and Europe.
The presen t study is aimed at identifying the allowable operating conditions for boilers using Cr-Mo steels. The effect of various factors on the spalling behavior of the oxide scale formed on Cr-Mo steels in steam was examined and analyzed.
Among all the factors consid ered, the thermal strain generated by the thermal shock showed the strongest effect on the spalling behavior. When the temperature difference of the innner and outer surface of the oxide scale was above 150 K, the spalling of the oxide scale on 2′ 1/4Cr-1Mo steel tube was observed in the thermal shock tests. The effects of other factors were found to be insignificant for the spalling of the oxide scale.

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Amorphous porous silica gels were prepared from organostannio derivatives of silicic acid. The treatment of tributylstannio ester of silicic acid with nitric acid afforded the silica gel with the elimination of tributylstannio moiety. It showed a relatively high distribution of 3.4 nm pores. Tributylstannio and dibutylstannio silica gels were analogously demonstrated to be useful precursors for the preparation of porous silica gels. The observed surface areas of these silica gels were in the range from 500m²/g-600m²/g.

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