American Cyanamid Company

Mark S Roby

Donald J Casey

Poly(glycolic acid)/poly(oxyalkylene) ABA triblock copolymers having the following formula: ##STR1## and wherein x and y have values which correspond to a total polyglycolide content of about 75 to 95 weight percent and a total polyoxyalkylene content of about 5 to 25 weight percent. The copolymers are useful for manufacturing fibers possessing a sufficiently low modulus of elasticity to permit their use as absorbable sutures having the requisite flexibility for use in monofilament form. A process of preparation involves purifying the hydroxyl-ended poly(oxyalkylene) and allowing it to react with glycolide to produce an ABA triblock copolymer of extrusion grade in which A represents a polyglycolic acid block and B represents a poly(oxyalkylene) block.

Poly(glycolic acid)/poly(oxyethylene) triblock copolymers and method of

A triblock copolymer having a proportion of units having the formula: ##STR1## as the end blocks, and the formula (I) randomly combined with a proportion of units having the formula: ##STR2## as the middle block finds particular advantageous use in manufacturing absorbable monofilament sutures and other surgical articles. A surgical article is manufactured from a synthetic absorbable copolymer formed by copolymerizing glycolide with 1,3-dioxan-2-one (trimethylene carbonate) wherein a combination of the monomers is substantially completely polymerized before the addition of the other monomer in the presence of a difunctional initiator at or below about 180.degree. C.; glycolide is added and the temperature increased up to about the melting point of poly glycolide to form a triblock copolymer with a proportion of units having the formula: ##STR3## as the end blocks, and the formula (I) randomly combined with a proportion of units having the formula: ##STR4## as the middle block.

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Stamford, CT, United States of America

Mark S Roby