The effects of aramid short fiber and CaCO3 nanoparticles inclusions on the elastic, damping, and thermal behavior of polypropylene composite

Abstract

Aramid short fiber (ASF) and calcium carbonate (CaCO3) nanoparticle were incorporated into polypropylene (PP) in an attempt to enhance the elastic, damping, and thermal performances. Different samples were melt mixed by employing a counter rotating twin-screw extruder and then compression molded using hot and cold presses, respectively. Scanning electron microscopy (SEM) studies displayed good dispersion and anchoring effect of the aramid fibers within the PP matrix. Differential scanning calorimetry (DSC) indicated higher crystal nucleating effect for the CaCO3 nanoparticles when compared to that of the aramid fibers. The influences of aramid fiber and CaCO3 nanoparticle on the elastic and damping components and glass transition temperature of composites were studied using a dynamic mechanical thermal analyzer under the fixed oscillation frequency, constant amplitude, temperature sweep, and dual cantilever geometry. The additions of aramid fiber and calcium carbonate (CaCO3) into PP noticeably increased the storage and loss moduli over a wide range of temperature (−50 to 150 °C). However, the effect of ASF was more prominent particularly at high temperatures. The incorporation of aramid fibers into PP enhanced the storage and loss moduli equal to 74% and 67%, respectively, at 100°C. Moreover, flexural tests under quasi-static loading were carried out, and the results indicated a greater capacity for the dynamic mechanical thermal analysis as compared to the simple mechanical tests in evaluating the composites. The anchoring effect of aramid fiber in PP matrix and the presence of CaCO3 nanoparticles in PP-aramid fiber interphase were found to be the key factors in achieving the improved rigidity, damping, and heat performances in PP/ASF/CaCO3 composites.