Influence of high power ultrasound on physical-chemical properties of polypropylene films aimed for food packaging: Barrier and contact angle features

Abstract : Investigation was focused on the impact of the high power ultrasound (HPUS) also called thermosonication, on the oxygen permeation properties (permeability, solubility and diffusion coefficients) of barrier films aimed for food packaging. For that purpose, biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) were used. Physical-chemical profile of samples was determined using goniometry. There is a significant impact only of extreme high power ultrasound conditions (the longest time and the highest amplitude) on the permeability, solubility and diffusion coefficients of oxygen through the BOPP films. The highest influence on the oxygen permeability in both investigated BOPP samples had a high power ultrasound (HPUS) with the amplitude of 100% during 6 minutes treatment. However, BOPP samples showed different sensitivity at lower HPUS treatments.