The dynamic mechanical properties of blends of phenolic resin (PF) and acrylic rubber (ACM) were investigated. PF had good compatibility with ACM and played an important role in the damping of the ACM/PF blends. With the increase of PF content and molecular weight, the peak of loss factor (tan 8) of blends shifted to a higher temperature and became much wider, indicating the convenience to adjust the value of tan 8 peak and the temperature range. Fourier Transform infrared spectroscopy detected that the intermolecular hydrogen bonding between the PF hydroxyl groups and the ACM carbonyl groups had made a great contribution to the improvement of damping. Compared with the organic small molecule used in our previous study, PF gifted the blends with equivalent damping performance and much better stability and a lower cost for the application of damping materials. (c) 2008 Wiley Periodicals, Inc.