A single carbon nanotube has many similarities with an individual polymer chain including the fact that the end-to-end length of both are often about the same and the diameter of the chain is about the same (for single-walled nanotubes) or only similar to 10 to 20 times larger (for multiwalled nanotubes). The combination of the solid surface and the similarity of the two materials means that polymer physics are altered in manners not seen with any other type of commonly used filler. The purpose of this review is to update a chapter that appears in a recent tome by Grady (2011) and describe how polymer physics is altered in composites that contain carbon nanotubes. Subjects that will be discussed include chain configuration, glass transition, polymer diffusion, unit cells and crystalline superstructure (lamellae, spherulites and shish-kebabs), and crystallization kinetics. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012