Surface properties of poly(ethylene oxide)-based segmented block copolymers with monodisperse hard segments

The surface properties of segmented block copolymers based on poly(ethylene oxide) (PEO) segments and monodisperse crystallizable tetra-amide segments were studied. The monodisperse crystallizable segments (T6T6T) were based on terephthalate (T) and hexamethylenediamine (6). Due to the crystallinity of T6T6T being high (~ 85%), the amount of amorphous T6T6T dissolved in the polyether phase was limited. The length of the PEO segments was varied (between 600 and 4600 g/mol) and effect of extending the PEO segments with terephthalic groups was investigated. Studied was the hydrophilicity of the surface by contact angle measurements and of the bulk copolymers by water absorption measurements The results were compared with data of PEO-poly(butylene terephthalate) (PEO-PBT) copolymers. For a given hydrophilicity of the bulk copolymer, the surface hydrophilicity decreased in the order PEO-PBT, PEO-T6T6T, and (PEO-T)-T6T6T. The use of short monodisperse hard segments resulted in low contact angles, with a lowest observed value of ~ 29°.