Preparation of Nanocomposites Based on LDPE/Perlite: Mechanical and Morphological Studies

Perlite nano-particles were prepared through a mechanical grinding process and surface-modified by poly(methyl hydrogen siloxane) (PMHS). Nanocomposites based on low-density polyethylene (LDPE) and different compositions of treated and untreated nano particles were prepared via melt mixing of the ingredients on a co-rotating twin screw extruder. Laser light-scattering (LLS) was used to analyze the mean particle size of the nano perlite while Fourier-transform infrared spectroscopy (FTIR) was employed to investigate surface modification of the particles. Scanning electron microscopy (SEM) was used to evaluate the dispersion status of the nano particles in the polymer matrix. Results indicated a relatively good dispersion of the particles (50-500 nm in size) within the LDPE matrix. Mechanical measurements showed remarkable increases in tensile strength and modulus of the nanocomposites containing surface modified perlite, compared to the neat polymer. Also, flexural strength and modulus were increased with increasing nano perlite, while impact properties were reduced.