Live poly(n-vinyl lactam) reactive stabilizers for dispersed phase polymerization
AssigneeRhodia Operations
InventorsMathias Destarac, James Wilson
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Abstract
The present invention concerns a method for preparing a polymer comprising a step (EI) for dispersed phase polymerization in the presence of a reactive stabiliser, wherein the following are brought into contact in an aqueous phase:—at least one ethylenically unsaturated monomer; —at least one source of free radicals; and—a reactive stabiliser comprising a polymer chain including monomer units (N-vinyl lactam) and a thiocarbonylthio-S group (C═S)—.
Claims12
A process for preparing a polymer, comprising a step (E1) of dispersed-phase polymerization in the presence of a reactive stabilizer, wherein the following are placed in contact in an aqueous phase:
- at least one ethylenically unsaturated monomer;
- a redox initiator comprising tert-butyl hydroperoxide as oxidizing agent, combined with a reducing agent selected from the group consisting of ascorbic acid and sodium sulfite;
- and
- a reactive stabilizer comprising a polymer chain including N-(vinyllactam) monomer units and a thiocarbonylthio group —S(C═S)—;
- wherein step (E1) is performed in the absence of surfactants.
Dependencies are inferred from the claim text.