The solvent uptake by vulcanized rubber particles was studied through a swelling technique by using a torque rheometer to record torque versus time curves, with good repeatability. Several experiments were performed to study the effects of varying the solvent/rubber ratio, the solvent type, and the rubber nature. The effects of the materials alone were also studied. A four-parameter mathematical model was developed, with a physical significance assigned to each of the parameters, and was compared with experiments. The model was found to fit well with the experimental results, therefore, allowing the physical processes involved in the solvent swelling of rubber particles to be investigated through model parameters. (C) 2004 Wiley Periodicals, Inc.