Method of preparing spherical porous bead-type polymers
AssigneeThe B. F. Goodrich Company
InventorsLouis Cohen, Pijus K. Basu
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Abstract
This invention relates to a new and improved quiescent polymerization process which produces spherical beads of polymer having excellent porosity and unusually high bulk density. The process comprises polymerizing discrete droplets of liquid monomer containing a monomer-soluble free radical type catalyst while suspended in an aqueous mucilage having plastic flow properties and in the presence of a nonionic surfactant having the proper Hydrophile-Lipophile Balance (HLB), such as, for example, sorbitan monooleate. The porous bead polymers have the advantage of providing for lower cost bulk shipping, better extrusion feed, and for easy monomer stripping.
Claims24
In a process for polymerizing one or more vinylidene monomers having a terminal CH.sub.2 .dbd.C<
- grouping in the form of discrete droplets containing a monomer-soluble free radical-type catalyst while suspended in an aqueous mucilage having plastic flow properties, said droplets being polymerized while moving under plastic flow in the substantial absence of shear forces, and said mucilage comprising a water-insoluble, water-swellable lightly cross-linked polymer of one or more olefinically unsaturated carboxylic acid monomers containing sufficient water to form a flowable plastic mass, the improvement comprising conducting said polymerization in the presence of a nonionic surfactant having a Hydrophile-Lipophile Balance in the range of about 1 to about 17, thereby producing spherical beads of polymer having high porosity and high bulk density.
Dependencies are inferred from the claim text.