Significantly Improving Strength and Damping Performance of Nitrile Rubber via Incorporating Sliding Graft Copolymer

Aiming at high-strength damping elastomers, the pre-cross-linked sliding graft copolymer (SGC) is incorporated into a nitrile rubber (NBR). The microstructure characterizations reveal that SGC phase is dispersed in NBR matrix fairly uniformly with a distinct interphase. As SGC content increases, the loss factor of SGC/NBR blends gradually increases. The improved damping properties of SGC/NBR blends are attributed to the intrinsic high damping characteristics of SGC and the formed interfacial hydrogen bonds. In addition, the mechanical properties of SGC/NBR blends are unexpectedly improved. The tensile strength of SGC/NBR (20/100) is increased by 170%, comparing to that of neat NBR. The significantly increased tensile strength is ascribed to the increased orientation of NBR chains, because of the “pulley effect” of SGC and the successive rupture/reassociation of interfacial hydrogen bonds. The high damping and mechanical properties of SGC/NBR blends make them potential materials for use in isolation rubber bearings applications.