Adhesion Strength Evaluation via Constrained Blister Test I. SIBS / Polystyrene and Polypropylene

Abstract

Abstract Adhesion of Styrene-Isobutylene-Styrene (SIBS) triblock copolymers to polystyrene and polypropylene was investigated at controlled ratios and molecular weights of the SIBS's polystyrene. Comparative studies of the cohesive and adhesive strengths were carried out using a carefully designed system based on monitoring a constrained blister growth. The acquired data was simulated mathematically to express adhesion main parameters of the energy of interfacial adhesion (γ) and dissipation coefficient (b). Polystyrene content of 30–40% in the SIBS exhibited maximum interfacial adhesion energy (γ) and, consequently, the highest adhesion strength compared to other SIBS samples of other polystyrene ratios. ATR-FTIR spectroscopic analysis and scanning electron microscopy (SEM) were carried out on both the substrate and the film surfaces before adhesion and after failure to assist understanding the failure process. Interpretation of SEM microphotographs and the ATR-FTIR confirmed the process to be adhesion in nature rather than cohesion.