Advanced processing of absorbable poly(p-dioxanone) containing high level of p-dioxanone monomer

A method of making absorbable poly(p-dioxanone) pellets by melt polymerization of p-dioxanone conducted in a single reactor with a temperature regulator, and comprising the steps of:

• i. charging a melt reactor with a mixture of p-dioxanone (PDO) monomer, initiator, catalyst, and optionally a dye;
• ii. melt polymerizing the mixture at a reaction temperature of between 95° C. and 145° C. in the melt reactor with sufficient agitation of the mixture to allow complete mixing of the monomer and for sufficient time to form a PDO polymer product having an unreacted PDO monomer content;
• iii. placing the PDO polymer product under a vacuum for about 60 to 180 minutes to remove at least portion of unreacted PDO, as measured by monomer content, wherein the unreacted PDO monomer content after step (iii) is between about 15 mole percent to about 35 mole percent;
• iv. discharging the PDO polymer product from the melt reactor directly into an in-line, underwater pelletizer to produce undried PDO pellets,
• v. collecting the undried PDO pellets, and
• vi. storing the collected PDO pellets in the freezer or a vacuum chamber.