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Synthesis and characterization of copolymers with the same proportions of polystyrene and poly(ethylene oxide) compositions but different connection sequence by the efficient Williamson reaction
Author(s) -
Huang Jian,
Wang Xuepu,
Wang Guowei
Publication year - 2015
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4891
Subject(s) - copolymer , ethylene oxide , materials science , polymer chemistry , polystyrene , crystallinity , polymerization , crystallization , anionic addition polymerization , micelle , end group , polymer , chemistry , aqueous solution , organic chemistry , composite material
The AB type diblock PS ‐ b ‐ PEO and ABA type triblock PS ‐ b ‐ PEO ‐ b ‐ PS copolymers containing the same proportions of polystyrene ( PS ) and poly(ethylene oxide) ( PEO ) but different connection sequence were synthesized and investigated. Using the sequential living anionic polymerization and ring‐opening polymerization mechanisms, diblock PS ‐ b ‐ PEO copolymers with one hydroxyl group at the PEO end were obtained. Then, using the classic and efficient Williamson reaction (realized in a ‘click’ style), triblock PS ‐ b ‐ PEO ‐ b ‐ PS copolymers were achieved by a coupling reaction between hydroxyl groups at the PEO end of PS ‐ b ‐ PEO . The PS ‐ b ‐ PEO and PS ‐ b ‐ PEO ‐ b ‐ PS copolymers were well characterized by 1 H NMR spectra and SEC measurements. The critical micelle concentration ( CMC ) and thermal behaviors were also investigated by steady‐state fluorescence spectra and DSC , respectively. The results showed that, because the PEO segment in triblock PS ‐ b ‐ PEO ‐ b ‐ PS was more restricted than that in diblock PS ‐ b ‐ PEO copolymer, the former PS ‐ b ‐ PEO ‐ b ‐ PS copolymer always gave higher CMC values and lower crystallization temperature ( T c ), melting temperature ( T m ) and degree of crystallinity ( X c ) parameters. © 2015 Society of Chemical Industry