Carol B Wasserman

US Patent:

48495026, Jul 18, 1989

Filed:

Feb 22, 1988

Appl. No.:

7/158450

Inventors:

Thomas L. Evans - Clifton Park NY
Carol B. Wasserman - Hartsdale NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

C08G 6362

US Classification:

528371

Abstract:

A phenol or bisphenol has been found effective as a chain transfer agent in the polymerization of cyclic carbonates to make hydroxyl-terminated polycarbonate oligomer of varying molecular weight.

US Patent:

50101439, Apr 23, 1991

Filed:

Nov 23, 1987

Appl. No.:

7/124127

Inventors:

Thomas L. Evans - Clifton Park NY
Carol B. Wasserman - Hartsdale NY
Timothy J. Shea - Schenectady NY
John R. Campbell - Clifton Park NY

Assignee:

General Electric Company - Schenectady NY

International Classification:

C08G 6548
C08G 6900
C08G 7112

US Classification:

525394

Abstract:

Block polyphenylene ether-polycarbonates are prepared by blending a mixture of at least one polyphenylene ether wherein all phenolic end groups are in the free phenol form; at least one cyclic polycarbonate oligomer, preferably an oligomer mixture; and a catalyst for conversion of cyclic polycarbonates to linear polycarbonates; and heating said mixture to polymerization temperature. The preferred catalysts are phenoxides, salts of polycarbonate oligomers and tetraphenylborate salts. The method may be conducted in the melt or in solution, and is adaptable for employment in reactive processing operations.