Influence of adding functionalized microparticles on the physical-mechanical, structural, and processability properties of thermoplastic rubber

The aim of this paper was to assess the influence of powders, modified on the surface with organic-inorganic compounds, on the block copolymer styrene-butadiene-styrene (SBS) type thermoplastic rubber properties, obtained by the mixing. Powder surface of kaolin, CaCO3, and MgCO3 modification with precursors of TiO2 and SiO2 aimed at improving the interface, dispersion, and physico-mechanical properties, of the composites based on SBS. Titanium isopropoxide was used as a precursor to TiO2, and for SiO2 the tetraethyl orthosilicate (TEOS). Modified powders were morpho-structural characterized by SEM, FTIR, and EDAX. FTIR spectra highlight the bands characteristic of individual powders, but functional groups derived from TiO2 and SiO2 could not be viewed. Due to this issue, it has resorted to an EDAX analysis of all the powders, and the presence of silicon and/or titan elements confirmed that modification occurred. SEM microscopy performed on modified versus the simple powder, shows a reduction of areas containing particle agglomerations, due to the reduction of surface energy and implicitly electrostatic, and attraction forces. The results of the physical-mechanical properties, show that for the composites containing mixture of modified particles (even at high amounts 75%) values of resistance to tear strength, elongation at break, elasticity, were superior to blends containing unmodified particles, to SBS respectively. The results obtained confirm that by modifying the particle surface, improves dispersion, and compatibility between phases, due to achieving optimal interface between particle/polymeric matrix. Melt flow index are lower for the reinforced SBS with high amounts of particles, but without raising issues of processability.