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 (TiO 2 ) nanoparticles are studied. These materials are of industrial interest, because they can be obtained by recycling PET bottles containing TiO 2 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 TiO 2 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 TiO 2 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/TiO 2 blend nanocomposite shows a balanced barrier character to both oxygen and water vapor. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 46986.