Sadanobu Katoh

Chemical modification of wood by anhydrides without solvents or catalysts.

Acetylated, propionylated, butyrylated, isobutyrylated, and hexanoylated woods were prepared at several temperatures. The reaction rate, dimensional stability, and changes in the ratios of specific gravity and dimensions in the tangential and radial directions were estimated. The reaction rate of propionylation was slow at temperatures under 90°C but increased with the temperature. The butyrylated, isobutyrylated, and hexanoylated woods showed little or no weight percent gain (WPG) and little or no antiswelling efficiency (ASE) below 110°C even for 24h, but they achieved significant WPG and ASE values at 140°C with a longer reaction time. The acetylated, propionylated, and butyrylated woods showed almost the same values for dimensional stabilization efficiency based on WPG (DSE). The specific gravity and dimensions ratios for acetylated, propionylated, and butyrylated woods compared to those of untreated wood increased with an increase in WPG.

Leachability, decay, and termite resistance of wood treated with metaborates

The formation of insoluble metaborates in wood was investigated by impregnating the wood with borax and metallic salts, after which their properties (e.g., leachability in running water and biological resistance) were evaluated. The solubility of three metaborates in acidic solutions was also evaluated. Double-diffusion treatment was carried out to form the precipitates of metaborates in sapwood specimens of Japanese cedar (Cryptomeria japonica) at room temperature. Water-saturated wood specimens were first impregnated by a saturated borax solution and then diffuse-penetrated with Zn2+, Ca2+, or Pb2+ solution. The precipitates of the three metaborates in the wood proved to be insoluble or hardly soluble in water by the leaching test. With the decay test using a brown-rot fungus (Fomitopsis palustris) and a white-rot fungus (Trametes versicolor) and with the termite test using a virulent subterranean termite (Coptotermes formosanus), the metaborate-treated woods showed generally good decay and termite resistance with negligible mass loss of the specimens. Particularly, the lead metaborate formed in the wood provided superb biological resistance against decay and termite attacks. In addition, the precipitates of these metaborates were found to be soluble in acidic solution, suggesting a way to remove these chemicals from wood when disposing of waste materials.

Leachability and Decay Resistance of Tetraphenylborate Salt-Treated Wood

Summary In order to reduce the leachability of boron compounds in wood, the double treatment of tetraphenylborate sodium salt [(C6H5)4BNa] (TPBNa) with potassium chloride (KCl) or tetramethylammonium bromide [(CH3)4NBr] (TMABr) was investigated by impregnating them into sapwood specimens of Japanese cedar (Cryptomeria japonica) to form insoluble salts of tetraphenylborate tetramethylammonium or tetraphenylborate potassium. The reduction of boron retention in treated wood specimens after the waterleaching test was very small, showing the good fixation of boron compounds in wood. The double treatment of TPBNa salts with TMABr or KCl solution also showed an excellent decay-resisting effect against both Coriolus versicolor and Tyromyces palustris at low boron retention.

Dimensional stability and flame resistance of silicate-acetylated and -propionylated wood composites

Abstract Silicate-acetylated wood (SAW) and silicate-propionylated wood (SPW) composites were prepared, and the dimensional stability and flame resistance of these composites were evaluated. The silicate gels had insignificant effects on the rate of acetylation or propionylation of wood. In the presence of silicate gels, the SAW and SPW composites showed slightly lower anti-swelling efficiency (ASE) during water or moisture absorption and a lower moisture excluding efficiency (MEE) than the corresponding acetylated wood and propionylated wood, but the SAW and SPW composites still retained fairly good dimensional stability. The oxygen indices (OIs) of the SAW and SPW composites were higher than those of untreated wood specimens and increased with an increase in the weight percent gains (WPGsiS) of silicate gel fixation. The silicate gel fixation endowed the composites with flame resistance.

Tree-to-tree and clone-to-clone variations of monoterpenes emitted from needles of hinoki (Chamaecyparis obtusa)

Variations in the composition of low boiling point (LBP) monoterpenes emitted from needle samples of 150 hinoki (Chamaecyparis obtuse) trees (30 strains, each with five clones) native to Shimane Prefecture, Japan, were investigated using a headspace technique. The assays revealed considerable proportional variations especially in the amount of sabinene, which ranged from 24% to 78% of the total LBP monoterpenes. The proportions of α-pinene, myrcene, and limonene negatively correlated with that of sabinene overall. In particular, the proportion of limonene showed clear negative correlation with that of sabinene (r = −0.98). Differences in the proportion of sabinene among five clones in each strain were less than 15% in 22 out of 30 strains, indicating that monoterpene composition is constitutively steady in most strains. In a few strains, however, considerable variation in the composition was observed among clones.

Individual variation in low boiling point monoterpenes emitted from hinoki (Chamaecyparis obtusa) needles.

Variations in the compositions of low-boilingpoint (LBP) monoterpenes in needle samples of 50 hinoki (Chamaecyparis obtusa) trees were investigated using the headspace technique. Considerable compositional variations were revealed, especially in sabinene composition. The sabinene composition varied from 4.9% to 78.0% of the total LBP monoterpenes.α-Pinene, myrcene, and limonene also showed considerable variations (9.0%–32.7%, 5.5%–22.6%, 3.6%–29.0% respectively). Analysis of the monoterpene composition allowed definition of four chemotypes based on the contingency table test. No correlation was observed between tree size and LBP monoterpene composition, indicating that the compositional variation in LBP monoterpene exists genetically in this population of hinoki.

Production and Characterization of Palm Fruit Shell Bio-Oil for Wood Preservation

Pyrolytic liquid (bio-oil), produced by pyrolyzing the shell of the palm fruit, was characterized, and its preservative properties were examined using drywood termites (Cryptotermes spp.) and blue stain fungi (Ceratocystis spp.). The yield from shell bio-oil production ranged from 35 to 37 percent relative to the mass of the raw material. The shell bio-oil had the following properties: specific gravity (ranging from 1.0365 to 1.0431), refractive index (ranging from 1.3594 to 1.3613), wood absorption level (ranging from 0.0088 to 0.0625 g/cm3), and retention (ranging from 0.0022 to 0.0141g/cm3). The shell bio-oil also had termicidal activity as shown by drywood termite mortalities: 25 percent between days 3 and 6, 50 percent between days 3 and 20, and 100 percent between days 5 and 49 in termite resilience tests. Using a fluorescence microscope, we demonstrated that the shell bio-oil–treated wood completely inhibited the growth of blue stain fungi on both pine (Pinus merkusii) and Sengon (Paraserianthes fa...

Composition of acidic components in Chinese raw tall oil

Chinese raw tall oil samples, which were obtained from pulp and papermaking factories in Qingzhou and Jiamusi, were first divided into acidic and neutral parts with a diethylaminoethyl-Sephadex (DEAE-Sephadex) gel column. The acidic components were then analyzed qualitatively and quantitatively by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results obtained are as follows: Most of the compounds that comprised 0.1% or more of the components were identified. Secodehydroabietic, 8,15-pimaradienoic, 8,15-isopimaradienoic, 7,13,15-abietatrien-18-oic acid, and others were found for the first time in Chinese tall oil; they have not been found in Chinese fatty rosin. Docosan-1,22-dioic acid was also found in tall oil for the first time.

Composition of neutral fractions in Chinese raw tall oil

Chinese tall oil samples, obtained from pulp and papermaking factories in Qinzhou and Jiamusi of China, were first divided into acidic and neutral fractions by saponification, extraction, and distillation. The obtained neutral fractions were then analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) after silylation with bis-(trimethylsilyl) trifluoroacetamide. The results obtained show that 10 types of compound (monoterpenes, sesquiterpenes, diterpenes, triterpenes, resin alcohols, resin aldehydes, steroids, fatty alcohols, phenols, stilbenes) exist in the neutral fractions of Chinese raw tall oil. In the neutral fractions from Qinzhou, 55 components were identified, 35 of which were found for the first time in Chinese raw tall oil; 12 components were discovered for the first time in raw tall oil. In the neutral fraction from Jiamusi, 45 components were identified, 9 of which were discovered for the first time in Chinese raw tall oil.

Effect of Fractionated Palm Fruit Shell Bio-Oil on Seed Germination

Palm fruit shell was pyrolyzed in a closed simple reactor. The physical and chemical properties of the pyrolytic oil (bio-oil) were characterized. The effect of original and fractionated bio-oil was analyzed as a germination promoting agent. Raw palm shell bio-oil character differed from that of wood and other biomass. The pyrolysis temperature caused differences in yield and acetic acid content, but there were no significant differences in specific gravity, pH, or the major chemical components of shell bio-oil. The effect of shell bio-oil on germination and radicle growth of seeds depended on pyrolysis temperature, fraction, and dilution rate. Original shell bio-oil had the best effect on germination and radicle growth. Dilutions of 102 and 103 inhibited germination and radicle growth for three kinds of seeds.