Method for preparing polymers by solid state polymerization
AssigneeGeneral Electric Company
InventorsGodavarthi Satyana Varadarajan, James Day, Bhaskar Bhairavnath Idage
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Abstract
Solid state polymerization of polycarbonates and polyesters is preceded by a step of contacting particles of an amorphous precursor polymer with a particulate material, typically a crystallized polycarbonate, which prevents adherence of the precursor polymer particles to each other. It is then possible to perform the solid state polymerization step without crystallizing the precursor polymer.
Claims22
A method for preparing a polymer by solid state polymerization which comprises:
- (A) contacting particles of an amorphous precursor polymer selected from the group consisting of polycarbonates and polyesters with at least one other particulate material having a melting point higher than the glass transition temperature of said precursor polymer, under conditions whereby said particulate material coats said particles to produce a coated polymer composition comprising a major proportion of said amorphous precursor polymer;
- and
- (B) subjecting said coated polymer composition to solid state polymerization conditions.
A coated precursor polymer composition comprising particles of which the major proportion is amorphous, said particles having a surface layer of at least one other particulate material having a melting point higher than the glass transition temperature of said precursor polymer.
Dependencies are inferred from the claim text.