AbstractThe rheological behavior of polypropylene/novolac blends was investigated with special reference to the effects of the blend ratio, compatibilization, and dynamic cure. The polypropylene and all the polypropylene/novolac blends presented evidence of shear‐thinning behavior. The novolac, compatibilizer, and dynamic cure had dramatic effects on the rheological behavior of the polypropylene. Various rheological plots, including plots of the viscosity, storage modulus, loss modulus, and loss angle, Han plots, and Cole–Cole plots, were used to analyze the polypropylene/novolac blends. The results showed that the compatibilization together with the dynamic cure could increase the viscosity and modulus because of the formation of a grafting polymer between the maleic anhydride grafted polypropylene and the curing novolac resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007