Crosslinking behaviors of acrylonitrile butadiene rubber (NBR)/poly(vinyl chloride) (PVC) alloy, filled with anhydrous copper sulfate (CuSO4) particles, were investigated for the first time by dynamic mechanical analysis (DMA) under hetero and isothermal modes, respectively. In the heterothermal testing, (NBR/PVC)/CuSO4 compound showed two marked increases in the storage modulus (E'), corresponding to coordination crosslinking of NBR-CuSO4 and self-crosslinking of NBR and PVC respectively. During the isothermal testing, a dramatic increase in E' was found at the initial stage while that of original NBR/PVC alloy was not detected. The marked increase in E' of (NBR/PVC)/CuSO4 compound was mainly due to the crosslinking induced by coordination between -CN and Cu2+. The increasing extent of E' increased with the rise of CuSO4 content, suggesting the formation of a greater number of crosslinks. Moreover, the activation energy (E-a) of crosslinking process was about 139 kJ/mol. In this work, fourier transform infrared spectrum (FT-IR) and equilibrium swelling method were also performed for the characterization of the compound. (c) 2006 Wiley Periodicals, Inc.