NBR/CR-Based High-Damping Rubber Composites Containing Multiscale Structures for Tailoring Sound Insulation

High-damping acoustic composites with unique sound insulation feature is reported, demonstrating surprisingly stable soundproof properties over a wide bandwidth of frequency (63-6300 Hz) with good mechanical properties. The extraordinary acoustic properties are attributed to the multiscale synergy of lamellar and hollow structures by multifillers adding. The acoustic composites are designed and fabricated through a low-temperature one-time rubber mixing process using nitrile butadiene rubber(NBR), chloroprene rubber (CR) as matrix and mica powder (MP), hollow glass beads (HGB), and montmorillonite (MMT) as multifillers. The soundproof mechanism is discussed in detail. Results indicate that the synergism of damping and sound absorption behaviors in the composition has a considerable impact on the acoustic characteristics, which can be controlled by the blending ratio of NBR/CR matrixes and the multiscale structures of MP/HGB/MMT multifillers. The designed multifillers acoustic composites can adapt to broadband engineering noise control including walls in express train constructions, panels of vessel or aircraft cabins, and large transportation pipelines.