In this study, effects of surface modification of calcium carbonate (CaCO3) nanoparticles with a single-layer of stearic acid were investigated on dispersion in polypropylene (PP) matrix. Two kinds of CaCO3 nanoparticles (monolayer-coated and uncoated) were used to investigate this effect. All combinations were mixed in a co-rotating twin screw extruder and then were injection molded. After breaking the injection molded parts in liquid nitrogen, effect of surface modification of nanoparticles on their dispersion in the PP matrix was investigated using a field emission scanning electron microscope (FESEM). The results showed good agreement between the measurements made with the TGA analysis and the existing theories. The surface modification of calcium carbonate nanoparticles using a single layer of stearic acid also had an effective influence on improving distribution and dispersion of nanoparticles in the PP matrix.

Carbon nanotubes (CNTs) have become strongly promising nano-particles for developingnovel smart polymer matrix nanocomposites to satisfy the ever increasing designrequirements of the recent avenues of space industry and other special structuralapplications. The objective of this paper is to investigate the influence of doped anddispersed CNTs in polymer matrix on its intrinsic properties. Three different types ofpolymers; polyvinylchloride (PVC), polymethylemethacrylate (PMMA), and polystyrene (PS)were subjected to this experimental investigation. CNTs/polymer matrix composites with acontent ratio of CNTs up to 5% by weight were synthesized in lab. The nanocomposites werethen characterized by measuring their mechanical, electrical, and thermal properties. Inaddition, thermo gravimetric analysis (TGA), Fourier transform infra red spectroscopy(FTIR), and scanning electron microscopy (SEM) were applied, and the results are presentedand discussed. It can be generally concluded that both PMMA and PS polymers disclosed muchbetter matching ability and cross linking ability with the interweaving CNTs than the PVC.Both PMMA and PS polymers may thus be nominated for further extension of the investigationto cover a wider range of CNTs content ratios in an endeavour towards searching formaximum specific performance properties of such nanocomposites.