A polymer includes directly bonded aromatic pendent groups and at least one moiety defined by one of the following formulas: >N-N=CR1R2 or -N=N-CR1R2- where R1 and R2 (a) are independently H or a substituted or unsubstituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, allyl, aralkyl, alkaryl, or alkynyl group, or (b) together form a substituted or unsubstituted alkylene, alkenylene, cycloalkylene, cycloalkenylene, or arylene group. The moiety can be attached to the polymer through one or both of the two open bonds and, where it is attached through only one bond, the other bond attaches to a hydrogen atom, i.e., the moiety is at a terminus of the polymer. Such polymers can be used to provide compositions that also include particulate fillers.