Effect of Synergistic Modification of Hollow Microspheres With Tannic Acid and Silane Coupling Agent on Natural Rubber Composites

ABSTRACT In this study, the effect of γ‐(2,3‐epoxypropoxy)propytrimethoxysilane(KH560) concentration on the relationship between filler and rubber matrix is investigated by using tannic acid (TA) and tetraethylenepentamine (TEPA) as intermediate reaction platforms for KH560‐modified hollow microspheres (RiM02) to enhance interfacial bonding between RiM02 and natural rubber (NR). In this process, the oxidized highly reactive quinone in TA reacts with the amino group in TEPA in a Schiff base reaction. This is followed by accelerating the reaction rate by metal ion complexation of Fe 3+ . Finally, the KH560 epoxy group reacts with it in a ring‐opening reaction. The NR/RiM02@KH560 composites are prepared by a mechanical blending method. The results show that adding KH560 improves the vulcanization rate and cross‐linking degree of the rubber composites, and the interfacial bonding between RiM02 and rubber is also improved. Compared with the composites with unmodified RiM02, the tensile strength, tear strength, and abrasion resistance of the RiM02‐TA@KH560‐9 composites are improved by 19.46%, 12.83%, and 18.42%, respectively. Meanwhile, the interfacial bonding between RiM02‐TA@KH560‐9 and the rubber matrix is the most significant, and the rubber composites possess the best rolling resistance and thermo‐oxidative aging resistance. These findings provide a reference value for hollow microspheres as fillers to reinforce rubber.