| Project/Area Number |
13555207
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
化学工学一般
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| Research Institution | Kobe University |
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Principal Investigator |
OHMURA Naoto Kobe University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50223954)
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| Co-Investigator(Kenkyū-buntansha) |
KATAOKA Kunio Kobe University, Faculty of Engineering, Professor, 工学部, 教授 (20031081)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥13,000,000 (Direct Cost: ¥13,000,000)
Fiscal Year 2003: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2001: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | Continuous emulsion polymerization / Nonlinear dynamics / Dynamic process / Bifurcation Phenomena / Self-sustained oscillation / Periodic operation / Unsteadiness / Particle aggregation / 多重安定性 / テイラー渦流反応装置 / 粒子径分布振動 / 重合率振動 / 粒子径分布 |
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| Research Abstract |
This research attempted to take advantage of the nonlinear dynamics in continuous emulsion polymerization processes in order to control latex particle size distribution. When the emulsion polymerization of vinyl acetate was conducted in a CSTR under conditions below the critical micelle concentration of the emulsifier, the monomer conversion attained in a time-independent steady-state operation showed a drastic rise from 0 to over 60% at a critical reaction temperature or mean residence time. The mean residence time or the reaction temperature was switched alternately between two values in the non-steady-state operation, one giving zero monomer conversion and the other a high monomer conversion in the usual steady-state operation. The periodic-switching operation induced oscillations in monomer conversion in time. The particle size distribution varied synchronously with the switching operation. This research showed the possibility of controlling the particle size distribution by adjust
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ing the frequency and/or the amplitude of the temporal variation of the mean residence time or reaction temperature. This research found that even while the constant monomer conversion was maintained at the steady state, the particle size distribution oscillated with a very large time period. This research revealed that the oscillations occur by a competitive interaction between polymerization reaction and aggregation of latex particles. In order to vary the colloidal stability of latex particles, a nonionic surfactant was added in some cases. It was found that using a mixture of a nonionic surfactant and an anionic surfactant was very effective for suppressing the oscillations. In order to take advantage of the oscillations of particle size, emulsion polymerization of vinyl acetate was performed in a system of two continuous stirred tank reactors in series. The oscillatory behavior could be controlled by varying the rotational speed of the impeller and the mean residence time. The research using two CSTR in series indicated the possibility of producing various poly-dispersed latex particles. Less
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