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Synthesis and properties of multiblock copolymers of styrene and propylene oxide
Author(s) -
Xie Hongquan,
Chen Xin
Publication year - 1988
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19880200107
Subject(s) - copolymer , polystyrene , propylene oxide , polymer chemistry , materials science , thermoplastic elastomer , styrene , epichlorohydrin , polyvinyl alcohol , toluene , toluene diisocyanate , polymer , polyurethane , chemistry , organic chemistry , ethylene oxide , composite material
Abstract Multiblock copolymers of styrene and propylene oxide were synthesized by coupling together poly(propylene glycol) and telechelic dihydroxy‐polystyrene with 2, 4‐toluene diisocyanate(TDI) as the coupling agent. The results showed that it was better to terminate the telechelic dihydroxy polystyrene with TDI first, then react with poly(propylene glycol). The copolymer obtained in this two‐step method contains less homopolymers than that obtained when all the three reagents reacted together in one step. The crude product can be purified by extractions with absolute ethyl alcohol and decalin in order to remove the unreacted poly(propylene glycol) and polystyrene, respectively. The purified products were characterized by IR, TH NMR, GPC, membrane osmometry, elemental analysis and shown to be multiblock copolymers of styrene and propylene oxide. The multiblock copolymer exhibits two transition temperatures(Tg's) and behaves like a thermoplastic elastomer at 20–30% polystyrene content. Addition or 2% of the copolymers to the blends of polystyrene and epichlorohydrin rubber improves evidently their mechanical properties and causes the two Tg's to become closer.