Polyethyleneterepthalate (PET) is widely used for beverage packaging materials. PET’s relatively low permeability for oxygen, carbon dioxide, and water, easy processability, and transparency make it as an excellent barrier material. Previous research within the group has performed detailed transport and sorption studies, especially evaluated any co-permeation effects of oxygen, carbon dioxide and flavor compounds in different morphologies of PET. Now, we will look for the next generation barrier materials by the combination of additives with PET. The overall goal is to establish the effect of additives (antiplasticizers and nanoplatelets) in PET on the transport properties for different gases, vapors, and their mixtures.