Patent ID: 7947748

Claim:
A method for preparing monodisperse crosslinked bead polymers comprising: (a) introducing droplets having a harmonic mean size from 50 to 1500 microns and comprising at least one monomer, at least one crosslinker and a free-radical polymerization initiator into an aqueous medium through orifices to produce an aqueous suspension of droplets having a volume fraction of droplets from 35 to 64%; wherein the droplets are not encapsulated; (b) causing the aqueous suspension of droplets to flow in a downward direction in a pipe such that: (i) a ratio of droplet harmonic mean size to inside pipe diameter is from 0.001 to 0.035; (ii) mean linear flow velocity is from 0.5 to 2.5 ft/s (0.15 to 0.75 m/s); and (iii) temperature is maintained at least 20° C. below a temperature at which the polymerization initiator has a half-life of 1 hour; and (c) polymerizing the droplets in a reactor.