The effectiveness of the chlorination treatment of synthetic vulcanized styrene-butadiene rubbers is determined by several experimental variables. In this study, trichloroisocyanuric acid (TCI) solutions in butanone have been used as chlorinating agents for a difficult-to-bond vulcanized styrene-butadiene rubber (R2). The influence of the TO concentration (0.5 and 2 wt% TCI/MEK) was studied and a comparison between the immersion and brushing procedures to apply the chlorinating agent has been carried out, Characterization of the chlorinated surfaces was carried out using contact angle measurements (water, 25 degreesC), ATR-IR spectroscopy, and scanning electron microscopy (SEM). T-peel tests on similarly treated R2 rubber/polyurethane adhesive joints were carried out to quantify adhesion. The chlorination by immersion of R2 rubber with TCI/MEK solutions was less effective than using a brush. The effects of the chlorination were similar using both procedures (creation of roughness, improved wettability, C-Cl moieties fort-nation and deposition of TO particles), but the extent of the modifications was more marked when using a brush. The higher concentration of chlorinating agent allows a higher degree of chlorination. Peel strength values were lower for brush-chlorinated R2 rubber because the migration of wax (which created a weak layer on the rubber surface) from the bulk to the R2 rubber surface was favoured. However, the presence of waxes on the R2 rubber surface still allowed a reasonable level of adhesion due to the predominance of polar moieties.