Control of hydrolytic degradation of polyglycolic acid using chain extender and anti‐hydrolysis agent

Abstract Biodegradable polyglycolic acid (PGA) shows great potential to substitute engineering petrochemical‐based polymers because of its high mechanical strength, stiffness, and gas barrier. However, drawbacks such as low melt strength, poor thermal stability, and rapid degradation limited its practical applications. In this paper, PGA was modified by reactive extrusion using chain extender (CE) and anti‐hydrolysis agent (AHA). The effects of the modification on the flow properties, melt viscosity and long‐term hydrolysis behaviors of PGA were studied. Compared with the unmodified but one‐pass processed PGA (C‐PGA), the melt mass flow rate of modified PGA (M‐PGA) decreased, while the complex viscosity (ω = 0.1 rad/s) dramatically increased, attributable to the realization of effective chain extension. The accelerated hydrolysis aging test indicated that the hydrolysis rate constant of C‐PGA at 30°C was 0.06183 day −1 , and that of M‐PGA was 0.01332 day −1 , which exhibited a 78% reduction. Correspondingly, the service life of M‐PGA was significantly prolonged. This may expand the potential applications of PGA, such as packaging film, agriculture, or textiles.