“…34 In the past decade, considerable research has been related to the development of sol-gel-synthesized in situ silica-based rubber composites. In those publications, the solgel approach has been successfully used to synthesize silica in different rubber matrices such as NR, [35][36][37][38][39]41,42,44,45 methyl methacrylate-grafted NR (MMA-GNR), 40 styrene-grafted NR (ST-GNR), 43 SBR, [44][45][46] vinyltriethoxysilane-grafted SBR (VTES-SBR), [47][48][49] EPDM, 34,44,[50][51][52][53] hydrogenated NR (HNR), 53 NBR, 54 CR, 55 and epoxidized NR (ENR). 56 Furthermore, sol-gel science is very effective to produce in situ silica in different rubber blend systems such as NR and NBR 57,58 and NR and CR.…”