The introduction of long-chain branching in polystyrene has the potential to improve some of the properties of the polymer. However, our attempts to make branched polystyrene in continuous free-radical bulk styrene polymerization processes has led to gel formation and eventual reactor fouling. This paper describes a new approach for introducing long-chain branching into polystyrene which would eliminate the reactor fouling problem. The approach is to place latent functionality on the polymer during polymerization which subsequently reacts to form branches upon thermolysis at temperatures > 200-degrees-C. This study focuses on the benzocyclobutene (BCB) moiety as the latent functionality. BCB is incorporated into the polymer chain by initiation with BCB functional peroxides, resulting in chain extension/branching upon heating at 240-degrees-C.