Effect of carboxyl end groups on hydrolysis of polyglycolic acid

Abstract

Abstract Dye interaction analysis in hexafluoroisopropanol was used to determine end carboxyl groups in polyglycolic acid (PGA). The rate of heterogeneous hydrolysis of purified PGA in water at 37°C shows a first‐order dependence on carboxyl end group concentration at levels above 12 meq/kg. Reaction of molten PGA with a tetraarylorthocarbonate or a triarylketenimine gave end‐capped PGA with carboxyl levels as low as 1 meq/kg. These samples were somewhat more resistant to hydrolysis than untreated PGA despite an increased initial rate at the lower carboxyl levels.