Poly(lactic acid), PLA, has gained increasing attention in the last decade as it can be obtained from renewable resources and is compostable. PLA has poor barrier properties against moisture vapor and oxygen. The barrier properties of PLA can be improved with silicon oxide (SiOx) coating. The aim of this study was to benchmark the thermal, mechanical and barrier performance of SiOx coated PLA bottles produced with the PlasmaxTM process against poly(ethylene terephthlate) (PET) bottles. Four different types of bottles were used: uncoated PLA(PLAU), SiOx coated PLA (PLAC), neat PET (PETS) and 3-layer co-extruded PET (PETM) with nylon as the middle layer. Bottles containing two simulants (alcohol and sugar/ acid solution) and a control (distilled water) were stored for 4 months at 37.8 °C and 70% RH. Bottles exposed to control and sugar/acidic solution showed loss of clarity in segments of the bottles, starting after 4 weeks of exposure. The heat deflection, glass transition temperature, tensile and compression strength for both PET and PLA bottles increased until week 8. After 16 weeks, coated as well as uncoated PLA containers exposed to alcohol solution became brittle. After exposure for 16 weeks, tensile strength and barrier properties decreased and showed statistically significant difference for uncoated and coated PLA bottles exposed to two simulants and the control solution. PET containers did not show any significant change as the length of exposure increased from 8 weeks to 16 weeks.
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