Synthesis and properties of hydrophilic segmented block copolymers based on poly(ethylene oxide)- ran-poly(propylene oxide)

The present article discusses the synthesis and various properties of segmented block copolymers with random copolymer segments of poly(ethylene oxide) and poly(propylene oxide) (PEO-r-PPO) together with monodisperse amide segments. The PEO-r-PPO contained 25 wt % PPO units and the segment presented a molecular weight of 2500 g/mol. The synthesized copolymers were analyzed by differential scanning calorimetry, Fourier transform infra-red spectroscopy, atomic force microscopy and dynamic mechanical thermal analysis. In addition, the hydrophilicity and the contact angles (CAs) were studied. The PEO-r-PPO segments displayed a single low glass transition temperature, as well as a low PEO crystallinity and melting temperature, which gave enhanced low-temperature properties of the copolymer. The water absorption values remained high. In comparison to mixtures of PEO/PPO segments, the random dispersion of PPO units in the PEO segments was more effective in reducing the PEO crystallinity and melting temperature, without affecting the hydrophilicity. Increasing the polyether segment length with terephthalic groups from 2500 to 10,000 g/mol increased the hydrophilicity and the room temperature elasticity. Furthermore, the CAs were found to be low 2239 and changed with the crosslink density. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1394-1404, 2010