Process for preparing poly(vinyl trifluoroacetate) and poly(vinyltrifluoroacetate/vinyl ester) copolymers in supercritical Co.sub .
AssigneeMinnesota Mining and Manufacturing Company
InventorsGilbert L. Eian, Cheryl L. S. Elsbernd
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Abstract
A method for the production of poly(vinyl trifluoroacetate) and copolymers thereof with vinyl esters is described. Poly(vinyl trifluoroacetate) (PVTFA) is obtained in relatively high yield under mild conditions by using carbon dioxide under supercritical conditions as a solvent. Synthesis of syndiotactic PVTFA on a commercial scale without the use of environmentally-harmful solvents is made possible by the invention, which provides a convenient route to syndiotactic polyvinyl alcohol.
Claims11
A method for the free-radical (co)polymerization of vinyl trifluoroacetate monomer comprising the steps of;
- (a) preparing a homogeneous mixture comprising:
- (i) vinyl trifluoroacetate monomer;
- (ii) optionally, vinyl ester monomer(s);
- (iii) supercritical fluid CO.sub.2 solvent;
- (iv) a peroxydicarbonate free-radical polymerization initiator;
- and
- (b) activating the mixture to effect precipitation (co)polymerization of the monomers and form a (co)polymer, while maintaining supercritical fluid CO.sub.2 conditions.
Dependencies are inferred from the claim text.