Solvent swelling of roll-cast triblock copolymer films

摘要: Abstract Polystyrene-polybutadiene-polystyrene triblock copolymers were roll-cast from toluene solutions to form globally oriented films. As-processed films, containing process-related residual stresses, exposed solvent vapours. Three solvents used in this study: toluene, which is a non-preferential for polystyrene and polybutadiene; methyl-ethyl-ketone, preferential the blocks; hexane, polybutadiene block. Microstructural changes accompanying swelling of films with cylindrical lamellar morphology monitored using two-dimensional small angle X-ray scattering. Solvent significantly improved symmetry hexagonal packing domains, was initially distorted due roll-casting flow field. also found improve long range order film morphology. Various phenomena accompany deswelling both three different used. Especially intriguing results observed case morphologies hexane. For morphology, after 1 h 2 subsequent d-spacing decreased by 18%. similar decrease 9% observed. Molecular models are presented explain these microstructural changes, that closely linked mobility glassy blocks, relaxation stress ability polybutadiene-polystyrene junctions at interfaces reposition accommodate volume changes.