From the above results, the following conclusions may be drawn: 1. A water ultrasonic procedure for cleaning SBR surfaces has been proposed. The peel strengths attained with polyurethane adhesives are not great and increase with the amount and especially with the viscosity of the adhesive. 2. Surface roughening improves the adhesion between SBR and PUA. There are no important changes in peel strength with the amount and viscosity of the PUA. Zinc stearate removal could be responsible for the increase in peel strength. 3. Chlorination of SBR surface increases the peel strength with regard to ultrasonic-cleaned rubber, especially when both SBR test strip pieces are halogenated. This increase depends on the solvent and percentage of TIC, as well as the amount and viscosity of the adhesive. However, the type of solvent for TIC does not induce physical differences in the SBR surface, the variations being explained in terms of the extent of the chlorine reaction with double carbon bonds of butadiene; in fact, IR spectra show some bands due to the C-C1 groups and also for carboxylic groups. On the other hand, SBR chlorination creates cracks in the surface which are larger when the amount of TIC increases. Furthermore, peel strength, contact angle, and surface analysis measurements correspond well. 4. There is a degradation of the PUA during the time when chlorine reacts with the SBR surface. This reaction is favored by large TIC amounts when MEK is the solvent, and there are low adhesive viscosities. 5. The variation of the adhesion strength with the percentage of TIC depends more on the kind of solvent employed to disperse the halogen-precursor than on the chemical nature of the polyurethane adhesive, probably due to a chemical reaction between them which leads to different chlorinated products.