Zinc oxide nanoparticles catalyze rapid hydrolysis of poly(lactic acid) at low temperatures

Poly(lactic acid) (PLA), a biobased, degradable polymer has been used recently in the field of oil and gas. These applications require rapid hydrolytic degradation of PLA especially at low temperatures. This work reports a simple and ready-to-scale up chemistry of using zinc oxide nanoparticles (ZnO NPs) to catalyze the hydrolytic degradation of PLA at the temperatures well below its glass transition temperature. Furthermore, for the first time, we have applied the nondestructive analytical method of 1H T2 NMR relaxometry to measure the apparent rate constants of PLA hydrolysis in solid, heterogeneous/composite systems that have multiple and complex reaction kinetics. We demonstrate that the activation energy for ZnO catalyzed PLA hydrolysis is about 38% lower than that of pure PLA hydrolysis. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40287.