(649a) Synergistically Enhancing Gas-Barrier and UV–Blocking Performance of Biodegradable Films Via Compositing with Aligned Graphene Nanosheets

Developing biodegradable polymer films that can replace traditional nondegradable polymers is urgently required to reduce the “White Pollution” caused by traditional polymers like polyethylene, polystyrene and polyethylene terephthalate. However, major biodegradable polymers such as poly (butylene adipate-co-terephthalate) (PBAT) show poor barrier performance for water vapor and oxygen, and they degrade rapidly under solar exposure due their low stability to UV light. To address these questions, in this work, we report the use of graphene nanosheets -- reduced graphene oxides (rGOx) as nanoinclusions to synergistically improve the gas barrier and UV-blocking performance of PBAT film. An alignment of rGOx in the film is achieved by using a biaxial orientation processing technique for the maximum reinforcement. Such PBAT/rGOx nanocomposite films demonstrate over 40% decrease of water vapor permeation and oxygen permeation compared with the pure PBAT film to 2.82×10^-11g·m·m^-2·Pa^-1·s^-1 and 7.4×10^-15cm³·cm·cm^-2·Pa^-1·s^-1 with low rGOx content of 0.035-0.35 vol%. The relevant values of polyethylene are ranged from 9.88×10^-12 - 6.08×10^-11 g·m·m^-2·Pa^-1·s^-1 and 7.98×10^-15 - 4.18×10^-14 cm³·cm·cm^-2·Pa^-1·s^-1 according to the polymer handbook. Elongation of PBAT/0.035% rGO film remains 167% while no mechanical strength of pure PBAT could be detected after an ageing test of 200 h. These results indicate that PBAT/ rGOx nanocomposite films with aligned rGOx nanosheets could become a sustainable substitute for packaging and agricultural film applications.