Abstract
Morphology control of poly(p-oxycinnamoyl) (POC) was studied to overcome the poor processability and microspheres were prepared by the self-organizing polycondensation of (E)-4-acetoxycinnamic acid (ACA) in aromatic solvent at 320°C without stirring. The work reported investigated the fabrication of POC needle crystals by hydrodynamically induced crystallization during polymerization of ACA. Polymerizations of ACA were carried out in a cylindrical vessel equipped with a stirring bar at a concentration of 1.5% under stirring with different speed (γ) of 300, 700 and 1100 rpm. Microspheres were obtained at γ of 300 rpm via liquid-liquid phase separation. In contrast to this, morphology was drastically changed from sphere to needle at γ of 700 and 1100 rpm These needle crystals were obtained with the yield of 22-27 %, which were 1.0-1.5 μm in length and 1.0-1.5 μm in width. The purely laminar flow in the cylindrical vessel at low stirring speed changed to Taylor vortices with the increase of γ and this brought about the huge concentration of oligomers along to the circular flow leading to the crystallization to form the needle crystals.
Original language | English |
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Number of pages | 1 |
Publication status | Published - Dec 1 2005 |
Event | 54th SPSJ Annual Meeting 2005 - Yokohama, Japan Duration: May 25 2005 → May 27 2005 |
Other
Other | 54th SPSJ Annual Meeting 2005 |
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Country/Territory | Japan |
City | Yokohama |
Period | 5/25/05 → 5/27/05 |
Keywords
- Crystallization
- Microsphere
- Needle crystal
- Polycondensation
- Polyester
- Stirring
ASJC Scopus subject areas
- Engineering(all)