Journal of Macromolecular Science Part B · 1977 · 17 citations · 18 references
Natural SciencesChemistryMaterials ScienceMaterials ChemistryPolymer ChemistryPolymer MaterialsPolymer CharacterizationPolymer MorphologyPolymer Phase BehaviorPolymer Physical ChemistryPolymer PhysicsPolymer StructureBlock Copolymer MorphologyCopolymers Phase BehaviorMolecular Weight Dependence Of Polymer PropertiesPolystyrene
Abstract Electron micrographs of a series of polyblends of poly(styrene-b-butadiene-b-styrene (SBS) and polystyrene (PS) are presented. These poly blends were cast from three different solvents, i.e., tetrahydrofuran—methyl ethyl ketone (THF/ MEK), benzene—heptane, and carbon tetrachloride. PS of four different molecular weights were used. It is shown that when the molecular weight of PS exceeds that in the block copolymer, a third phase in the form of “islands” is formed. Lamellarlike structures are formed in the block domains upon the addition of homopolymer. Stretching perturbs the morphology of the block domains somewhat, and produces craze marks in the PS islands. The craze marks are removed upon annealing. These results are discussed in conjunction with the observed mechanical behavior of the same polyblends reported in Part I of this series.
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