Relationship between the structure and thermophysical property of a starch-synthetic polymer composite under heated and pressurized conditions

Research Project

Project/Area Number	09650820
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	化学工学一般
Research Institution	Tohoku University
Principal Investigator	TSUKADA Takao Institute for Chemical Reaction Science, Tohoku University Associate Professor, 反応化学研究所, 助教授 (10171969)
Co-Investigator(Kenkyū-buntansha)	HOZAWA Mitsunori Institute for Chemical Reaction Science, Tohoku University Professor, 反応化学研究所, 教授 (70005338)
Project Period (FY)	1997 – 1998
Project Status	Completed (Fiscal Year 1998)
Budget Amount *help	¥2,700,000 (Direct Cost: ¥2,700,000) Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000) Fiscal Year 1997: ¥1,900,000 (Direct Cost: ¥1,900,000)
Keywords	starch / synthetic polymer / composite / themal conductivity / transient hot wire method / pressure
Research Abstract	Use of agriculturally derived products such as starch and replacement for totally synthetic polymers reduce our dependence on petrochemically derived monomers, and are currently an active research area because of the biodegradability of these plant-derived materials, It is important to acquire the fundamental data such as the thermophysical properties for the design and optimization of the apparatus to produce such materials, In the present work, the thermal conductivity of a starch-synthetic polymer composite was measured under heated and pressurized conditions, and the following conclusions were obtained. 1) Development of the probe to measure thermal conductivity of the material The probe for thermal conductivity measurement of food materials under heated (- 150ﾟC) and pressurized conditions (-20MPa) has been developed, being based on the transient hot wire method. 2) Thermal conductivity measurement of starch gel After the validity of the data measured using the probe was verified by c … More omparison with published data of water, the thermal conductivity of gelatinized potato starches was determined at 25-80ﾟC, 50-80 % moisture, and 0.2-10 MPa. It was found that the thermal conductivity of the starch gel increases with temperature and moisture content, and that it increases with pressure up to I MPa, above which it remains almost constant. The pressure dependency can be justified by considering the presence of entrapped fine air bubbles which could have penetrated into the sample during the preparation process. 3) Thermal conductivity measurement of starch-synthetic polymer composite The thermal conductivity of starch-graft-poly(methylacrylate), which was prepared by ceric ammoniumnitrate-initiated polymerization of methylacrylate onto granular corn starch, was determined at 20-80ﾟC, 7-35%moisture and 0.2-8 MPa. It was found that the thermal conductivity increases with temperature and moisture content, although the temperature dependency is so small. Also, the thermal conductivity increases with pressure due to the same reason as 2). Less