The effect of nanoperlite and its silane treatment on thermal properties and degradation of polypropylene/nanoperlite nanocomposite films

The main goal of this study is to observe the exact effect of nanoperlite and its silane treatment on thermal behavior and degradation mechanism as well as thermomechanical properties of nanocomposites. In this regard, polypropylene (PP) with various contents of untreated nanoperlite and silane treated nanoperlite were prepared using a twin-screw extruder and an extrusion film blew machine. Regardless of the type, the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) tests show no chemical reaction between PP and nanoperlite and relatively good dispersion of nanoparticles was obtained in the system. The results of thermal studies represent a reduction in all the properties of nanoperlite/PP nanocomposites including thermal stability, while, the addition of silane treated nanoperlite shows less reduction and better thermal stability. Based on Flynn-Wall-Ozawa method, thermal degradation kinetics and mean activation energies of the untreated nanoperlite filled nanocomposites show higher values. Finally based on thermomechanical studies, treated nanoperlite-filled nanocomposites show lower values for tan D comparing to untreated nanoperlite-filled nanocomposites, as the storage modulus is reinforced and the loss modulus decreased. Overall, nanocomposites with 2–4% of treated nanoperlite showed nearly the same behavior of 4–6% of untreated nanoperlite filled nanocomposites and due to better dispersion, thermal and morphological properties, these films can be proper alternatives for packaging industries.