Lamellar crystalline structure of star‐shaped block copolymers with an amorphous block of polystyrene and two crystallizable blocks of poly(ethylene oxide)

Abstract

AbstractStar‐shaped block copolymers S(EO)2 with two poly(ethylene oxide) chains (PEO) linked to the same end of a polystyrene chain (PS) exhibit a lamellar liquid crystalline structure, with crystallized and folded PEO chains, in the dry state as well as in the presence of a preferential solvent of the PS block at temperatures below about 50°C. Refolding of the PEO chains was studied in terms of the PS swelling degree and in terms of the PEO content of the copolymers. A difference in length of the PEO chains was suggested, probably resulting from the different nature of the sites that initiate the EO chain polymerization. To investigate the effect of the number of the PEO chains fixed to the PS block, two block copolymers S(EO)2 and SEO of the same relative molecular mass and composition were studied.