Suspended Droplet Polymerization in an Unstable, Vibrating Shallow-Bed Reactor
© 2016 American Chemical Society. A piston-driven shallow bed reactor (5.9 cm high) was used to conduct suspension polymerization under unstable flow conditions, which produced excellent mixing and droplet breakage. The instability started at the air/solution interface and carried through to the complete solution volume. The liquid interfacial instability described in the classic paper on this subject [T. B. Benjamin and F. Ursell, Proc. R. Soc. London A, Math. Phys. Sci. 1954, 225, 505-515] leads to a set of Mathieu equations, which map out regions of instability to guide the selection of amplitude and frequency. The current work operated exclusively in the half-frequency region of the instability curves. The performance was compared with a conventional impeller reactor. Both reactors operated in the power range of 0.3-20 W/kg. Only the piston reactor was capable of producing microparticles smaller than the Komolgorov scale, for the amine-initiated Michael addition of a trithiol to a triacrylate. The Hinze breakage model was used to correlate the mean particle sizes for impeller work. The pulsed-piston reactor particle size data required testing sub-Kolmogorov models to fit the mean particle size, and a viscous model [R. Shinnar, J. Fluid Mech. 1961, 10, 259-275] gave a good fit. Reactions conducted in the stable region of the Mathieu equation were highly ineffective.
Publication Source (Journal or Book title)
Industrial and Engineering Chemistry Research
Abedin, R., Pojman, J., Knopf, F., & Rice, R. (2016). Suspended Droplet Polymerization in an Unstable, Vibrating Shallow-Bed Reactor. Industrial and Engineering Chemistry Research, 55 (8), 2493-2503. https://doi.org/10.1021/acs.iecr.5b04216