Environmental friendly surface treatments of styrene-butadiene-styrene rubber: alternatives to the solvent-based halogenation treatment

Corona discharge and UV radiation treatments modified the S6 rubber surface by creating C-O, C=O and COO− moieties that improved wettability. The extent of the surface modifications of S6 rubber was different by treatment with UV radiation or corona discharge. The higher the corona discharge energy or the higher the length of the UV radiation treatment, the more marked modifications were achieved on the S6 rubber surface. On the other hand, corona discharge and UV radiation treatment produced different morphologies on the S6 rubber surface. The poor adhesion obtained with the corona discharge treatment has been ascribed to a lack of surface roughness and/or the creation of weak boundary layer on the S6 rubber. On the contrary, UV radiation treatment produced cracks on the S6 rubber surface that favored the mechanical adhesion. The modifications produced by both treatments were compared to those produced by the solvent-based halogenation treatment.