Poly(ethylene terephthalate)-based nanocomposite films as greenhouse covering material: Environmental sustainability, mechanical durability, and thermal stability

The environmental sustainability, mechanical durability, and thermal stability of the poly(ethylene terephthalate) (PET)-based nanocomposite films compared with pure PET were evaluated. The samples were obtained by incorporating 2 wt% of TiO2, SiO2, ZnO nanoparticles (NPs), and an equal mixture of NPs in polymer by melt-mixing in a twin-screw extruder. The mechanical properties and hardness of samples were determined by the tensile and the atomic force microscopy-based nanoindentation tests. The melting, crystallization, and glass transition temperatures of samples were studied by dynamic mechanical thermal analysis and differential scanning calorimetry. The effects of compatibility, dispersity, and hydrophobicity of NPs on the surface morphology, crystallinity, and thermomechanical properties of nanocomposites were studied. The interaction of SiO(2)NPs with PET chains had a promising effect on the surface morphology, high elastic modulus, dispersibility, crystallinity, and thermostability of the sample. The mixing of ZnO and TiO(2)NPs improved the UV-blocking effects, and photostability, while the SiO(2)and TiO(2)NPs maintained the thermal properties of the film against UV radiation. The resulting film could be a good candidate as a greenhouse covering material due to its suitable photosynthetically active radiation transmittance.