Effect of surfactant treated boehmite nanoparticles on properties of block copolymers

The effectiveness of reinforcement of a polymer is known to depend on the strength of the interfaces between the reinforcement and the matrix. We have used polystyrene and a styrene–butadiene–styrene (SBS) copolymer as matrixes and ceramic boehmite γ-AlO(OH) as reinforcement. We have applied boehmite both untreated and treated with sulphonic acid based surfactants with different alkyl groups. As expected, the coupling agents improve the adhesion between the polymers and the ceramic filler. The presence of boehmite and treatments affect the glass transition temperatures determined by dynamic mechanical analysis, nanoindentation hardness hnanoindent as well as Vickers microhardness hVickers. For SBS and SBS containing composites, the hnanoindent/hVickers ratio is a constant.