Polyethylene Terephthalate/Low Density Polyethylene/Titanium Dioxide Blend Nanocomposites: Morphology, Crystallinity, Rheology, And Transport Properties

Physical features of polyethylene terephthalate (PET)/low density polyethylene (LDPE) immiscible blends, rich in PET, with and without titanium dioxide (TiO2) nanoparticles are studied. These materials are of industrial interest, because they can be obtained by recycling PET bottles containing TiO2 with their corresponding polyethylene made caps. Their potential application in packaging is investigated. Droplet-matrix morphology is observed by scanning electron microscopy; coalescence occurs during compression molding. Transmission electron microscopy results show that TiO2 nanoparticles are located at the interface between PET and LDPE, forming a physical barrier that favors development of smaller droplets. Thermal analysis results are compatible with the morphology of the blends and the location of the TiO2 nanoparticles. Viscosity obtained by extrusion continuous flow and oscillatory flow measurements in the linear regime show that some of the blends have viscoplastic behavior. Permeability results reveal that 80PET/20LDPE/TiO2 blend nanocomposite shows a balanced barrier character to both oxygen and water vapor. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46986.