| 摘要 |
<p>Method and apparatus for preparing polymer beads of uniform particle size by suspension polymerization. A monomer solution of polymerizing monomers containing initiators is jetted into an upwardly flowing stream of monomer droplets through a plurality of orifices of 50-300 micron sizes at the bottom of a vertically located monomer droplets forming reaction vessel in a pulsating manner at a flow rate of 2-4 litrs per hr and at a pressure of 0.2 to 1 Kg/cm 2 and simultaneously a liquid solution immiscible with the monomers and containing suspension stabilizers is cocurrently jetted into an upwardly flowing stream through a plurality of holes of 0.5 - 1 mm sizes at the bottom of the reaction vessel spaced above and around the outer periphery of the orifices in a pulsating manner at a flow rate of 4-8 litrs per hr and at a pressure of 2.5 to 3 Kg/cm 2 . The ratio between the monomer solution and the liquid solution is 1:10 v/v and the holes are spaced above the orifices at a distance of 10-40mm. The monomer droplets in the liquid solution are allowed to rise up in the reaction vessel in a controlled and smooth manner under the dynamic forces exerted by differential flow rate and differential pressure between the pulsating monomer solution and liquid solution supplies and the differential densities between the monomer and liquid solutions without causing coalescence, agglomeration and breakup of the monomer droplets and to stabilize by partial polymerization of the droplets by the suspension stabilizers in the liquid solution at 50 to 60°C in the reaction vessel. The monomer droplets in the liquid solution are allowed to flow out from the reaction vessel horizontally into a polymerization reactor fitted with agitator and located at an elevated position with respect to the reaction vessel and get polymerized in the polymerization reactor at 80-85°C. The polymer beads are dried at 80 to 100°C and sieved. The invention is simple to carry out, reduces energy requirement and cycle time and is cost effective.</p> |
