Construction of PDMS-crosslinked tread composites that feature high energy-saving and anti-thermal oxidative performances

Abstract

Herein, we reported the synthesis of a siloxane-containing polysulfide poly(S-EGAE-PDMS) by combination of inverse vulcanization and dynamic covalent polymerization. By virtue of polysulfide, hydroxyl, and polydimethylsiloxane (PDMS) moieties, poly(S-EGAE-PDMS) can act as both vulcanization agent and interfacial modifier in rubber composites through the reaction with the rubber chains and silica/carbon black nanofillers. The uniform dispersion of nanofillers and enhancement of filler-rubber matrix interfacial interactions were achieved. Successful incorporation of PDMS segments as the crosslinks between butadiene-isoprene rubber chains was proved. Tensile test and dynamic mechanical analysis revealed the poly(S-EGAE-PDMS)-based tread had higher mechanical properties compared to the conventional sulfur-crosslinked congener, the tensile strength and toughness increased by 19.8% and 19.3%. The rolling resistance decreased by 12.1%, and the high bond dissociation energy of −Si-O- crosslinks led to an increase of anti-thermal oxidative aging property by 19.1%. Moreover, the dynamic covalent –S-S– and –Si-O-Si– bonds endowed the poly(S-EGAE-PDMS)-crosslinked rubber material good recyclability.