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Reduction of acetaldehyde formation from pulverized solid woods by thermal and chemical treatments
Mizukoshi, Atsushi,Kurosaki, Yosuke,Yamamoto, Naomichi,Noguchi, Miyuki,Iizuka, Atsushi,Yamasaki, Akihiro,Yanagisawa, Yukio Springer-Verlag 2018 Wood science and technology Vol.52 No.2
<P>High concentrations of acetaldehyde are often observed in indoor environments. One possible source of this is acetaldehyde formation produced by ethanol from wood building materials. To characterize indoor acetaldehyde formation and propose methods for its reduction, chamber-based experiments were conducted in which alcohols were added to pulverized solid woods. The results indicated that acetaldehyde was generated from the ethanol-added wood materials, and softwoods, namely Japanese cedar, Japanese cypress, and Swedish redwood generated more acetaldehyde than the other three woods. The experiments using different types of alcohols of methanol, ethanol, 1-propanol, and 2-propanol revealed a tendency similar to the reported enzymatic profile of the higher plant-derived alcohol dehydrogenase. It was confirmed that acetaldehyde generation was reduced by treatment methods typically used for inactivating enzymes, namely chemical treatments using pyrazole, borate, and urea and thermal treatments. The findings suggest that the chemical and thermal treatment methods are useful to reduce acetaldehyde generation in indoor environments.</P>
( Ken Kojio ),( Shuhei Nozaki ),( Atsushi Takahara ),( Satoshi Yamasaki ) 한국고무학회 2019 엘라스토머 및 콤포지트 Vol.54 No.4
Polyurethane elastomers (PUEs) were synthesized using trans-1,4-bis(isocyanatomethyl) cyclohexane (1,4- H6XDI), poly(oxytetramethylene) glycol, 1,4-butanediol (BD), and 1,1,1-trimethylol propane (TMP). To control the molecular aggregation state and mechanical properties of these PUEs, hard segment contents of 20 and 30 wt% and BD/TMP ratios of 10/0 and 8/2 were chosen. Differential scanning calorimetry and small-angle X-ray scattering measurements revealed that the degree of microphase separation increased with an increase in both hard segment content and BD ratio. The Young’s modulus and strain at break of the 1,4-H6XDI-based PUE were 6-20 MPa and 5-15, respectively. Incorporation of 20% TMP as a cross-linking agent into BD increased the melting temperature of the hard segment chains, that is, heat resistance, and decreased the Young’s modulus. This could be due to the low density of the physical cross-linking network and the dispersion of hard segment chains in the soft segment matrix in the PUE in the presence of 20% TMP.
Kojio, Ken,Nozaki, Shuhei,Takahara, Atsushi,Yamasaki, Satoshi The Rubber Society of Korea 2019 ELASTOMERS AND COMPOSITES Vol.54 No.4
Polyurethane elastomers (PUEs) were synthesized using trans-1,4-bis(isocyanatomethyl) cyclohexane (1,4-H6XDI), poly(oxytetramethylene) glycol, 1,4-butanediol (BD), and 1,1,1-trimethylol propane (TMP). To control the molecular aggregation state and mechanical properties of these PUEs, hard segment contents of 20 and 30 wt% and BD/TMP ratios of 10/0 and 8/2 were chosen. Differential scanning calorimetry and small-angle X-ray scattering measurements revealed that the degree of microphase separation increased with an increase in both hard segment content and BD ratio. The Young's modulus and strain at break of the 1,4-H6XDI-based PUE were 6-20 MPa and 5-15, respectively. Incorporation of 20% TMP as a cross-linking agent into BD increased the melting temperature of the hard segment chains, that is, heat resistance, and decreased the Young's modulus. This could be due to the low density of the physical cross-linking network and the dispersion of hard segment chains in the soft segment matrix in the PUE in the presence of 20% TMP.