Microscopic Interaction of Oleated Cellulose and Silica in Dual-Filled Elastomers.

The quantification of interactions between fillers and filler with elastomers in nanocomposites relies on the combination of different microscopy techniques. Small Angle X-ray scattering is a key method for the identification of the filler network morphology at the nanoscale. Hybrid nanocomposites containing fillers with diverse morphology and reinforcing ability represent considerable complexity thereby justifying ongoing research in this area, as a consequence of the multiple interactions between fillers and also the filler with the elastomer. Therefore, a microscopic structural investigation of a dual-filled elastomer for tire applications is presented. Chemically modified micro-fibrillated cellulose in combination with traditional silica filler dispersed by melt processing in a styrene-butadiene (SBR) random copolymer were investigated. Small-Angle-X-ray Scattering and Scanning-transmission-electron-microscopy (STEM) revealed non-mixing of the two fillers on the silica scale and the predominant formation of individual filler clusters. Through a novel data deconvolution procedure, partial structure functions corresponding to the contribution of each filler to the scattering function were extracted. This approach offers a suitable methodology to identify the compatibility between morphologically different fillers and their mutual effect on the dispersion.