Physicomechanical study of random polypropylene filled with treated and untreated nano-calcium carbonate: Effect of different coupling agents and compatibilizer

摘要

Random polypropylene copolymer is blended with 2-10% nano-calcium carbonate (nCaCO3) with and without maleic anhydride-grafted ethylene-propylene rubber ([EPR] MA-g-EPR) using two different titanate- and silane-coupling agents. The nanocomposites were prepared with fatty acid (oleic and stearic acid) surface-treated and -untreated nCaCO3 and random polypropylene. Surface-treated nCaCO3 and EPR (MA-g-EPR) were used as a modifier in nanocomposites and characterized with the help of X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The physicochemical properties like density, melt flow index and heat distortion temperature were evaluated beside their mechanical properties (tensile, flexural and impact strength). It was found that the favorable surface development is taking place at the interface of coupling agent and surface-treated nCaCO3, and this linkage is responsible for tensile properties. The untreated nCaCO3 shows more reinforcement with matrix for the reason that there is no long alkyl group present at the interface. Beyond a certain limit, increased trends of nCaCO3 in composite do not show more reinforcing effect due to agglomeration of nCaCO3.