(589g) Poly(ethylene terephthalate) Barrier Enhancement Through Engineered Antiplasticization

While poly(ethylene terephthalate) (PET) has been the industry standard for soft-drink bottles over the last four decades, more stringent requirements on the barrier properties to oxygen are needed if PET is to expand into more demanding markets (juice, etc). This work promotes modifying the current processing platform through an antiplasticization-based approach to improve the barrier properties of PET. Fundamental O₂ and CO₂ permeation and sorption transport studies are used to evaluate the performance of amorphous PET mixtures with a proprietary low molecular weight antiplasticizing compound identified by the Coca-Cola Company, known as PLEMAT. Additionally, the effect of PLEMAT on the polymer/diluent structural properties as compared to pure PET will be quantified through a DMA investigation of the activation energies and entropies associated with the low temperature beta relaxation. The concept of free volume is also applied to correlate the permeation and specific volume data to literature results, and to serve as a fundamental metric to track the progress of antiplasticization.