Mechanical and Gas Barrier Properties of Poly(L-Lactic Acid) by Plasma-Enhanced Chemical Vapor Deposition of SiOx

ABSTRACT In this work, poly(L-lactic acid) film was coated with SiOx by the plasma-enhanced chemical vapor deposition with different deposition times. Compared with the neat poly(L-lactic acid) film, the oxygen (O2), carbon dioxide (CO2), nitrogen (N2), and water vapor permeability of the poly(L-lactic acid)/SiOx60 film (depositing for 60 min) decreased by 40.7, 30.6, 58.7, and 53.4% at 25°C, respectively. After treated by the SiOx deposition, the gas permselectivity of the poly(L-lactic acid)/SiOx60 film, such as α(CO2/O2), α(O2/N2), and α(CO2/N2), increased by 17.2, 43.9, and 67.5% at 25°C, respectively. In addition, Young’s modulus and tensile strength of poly(L-lactic acid)/SiOx60 film increased by 107.2 and 49.3%, respectively. Moreover, the poly(L-lactic acid)/SiOx60 films still kept good toughness with an elongation at break of 50.7%. GRAPHICAL ABSTRACT