Abstract

Poly(ethylene terephthalate)/poly(lactic acid) (PET/PLA) blends with composition of 90/10 and 75/25 (wt /wt ) along with two types of graphenic materials, namely graphene oxide (GO) and exfoliated graphite (xGnP), were prepared through one-step melt mixing process. The Thermal, thermo-oxidative, and hydrolytic degradation characteristics of the developed degradable PET-based nanocomposites were investigated. Thermal degradation studies by thermogravimetry analysis and melt rheological analysis in N2 atmosphere, revealed that unlike xGnP, the addition of GO to the blends reduced their thermal stability leading to reduction of viscosity and elasticity of the blends. The behavior was attributed to the role of GO in enhancing the chain scission reactions. In the air atmosphere, the barrier properties of the graphenic materials prevailed. Compared to xGnP, the relatively well-dispersed GO showed better barrier against oxygen and increased the thermo-oxidative stability of the blends. Investigation of the hydrocatalytic degradation of developed systems, at different pH of 2 and 4, over a period of 40 days at 37 °C, showed that the amount of weight loss of the GO-containing nanocomposite systems was higher than that of xGnP. The overall results of thermal, thermo-oxidative, and hydrocatalytic degradation studies confirmed the prominent role of GO in the development of degradable PET-based products. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48466. © 2019 Wiley Periodicals, Inc.