Polyblends of Poly(Styrene-b-Butadiene-b-Styrene) and Polystyrene. II. Electron Microscopy.
CALIFORNIA UNIV BERKELEY DEPT OF CHEMICAL ENGINEERING
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Electron micrographs of a series of polyblends of polystyrene-b-butadiene-b-styrene, SBS, and polystyrene, PS, are presented. These polyblends were cast from three different solvents, i.e., tetrahydrofuranmethyl ethyl ketone THFMEK, benzeneheptane 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. Lamellar-like 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.
- Polymer Chemistry
- Elastomers and Rubber