Development and Testing of a Novel High-Damping Chlorobutyl Rubber for Structural Viscoelastic Damper Devices

The main objective of this study is to modify the blend formulation of a Chlorobutyl rubber compound to improve its damping properties for structural applications. A new rubber composite was created by adding Acrylonitrile Butadiene Rubber (NBR) and Chlorinated Polyethylene (CPE) to Chlorobutyl rubber. The viscoelastic parameters of the cured original CIIR (control sample) and modified CIIR (i.e., CIIR/NBR/CPE) compounds were determined by Dynamic Mechanical Thermal Analysis (DMTA) in tension mode. Subsequently, cyclic shear tests were performed at room temperature and loading frequencies of 0.5, 0.75, 1 and 3 Hz on prototype viscoelastic damper devices fabricated from the rubber blends. The shear force-deformation hysteresis loops of the prototype dampers at shear strains of 0.5, 1.0 and 1.5 revealed that the viscoelastic properties (i.e., shear storage and loss moduli as well as loss factor) of the modified CIIR significantly improved as compared to the original CIIR. The test results demonstrated an increase exceeding 100% and 160% in the shear storage and loss moduli, respectively, of the modified CIIR compared to the reference CIIR.