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Preparation and characterization of cyclic poly(oxypropylene)
Author(s) -
Yu GaEr,
Sinnathamby Prash,
Sun Tao,
Heatley Frank,
Price Colin,
Booth Colin
Publication year - 1997
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.1997.030181212
Subject(s) - acetal , molar mass , dichloromethane , yield (engineering) , polymer , polymer chemistry , chemistry , molar ratio , mass spectrum , molar mass distribution , materials science , organic chemistry , mass spectrometry , chromatography , catalysis , composite material , solvent
Poly(propylene glycol) [α‐hydro‐ω‐hydroxypoly(oxypropylene)] of number‐average molar mass M̄ n ≈ 2000 g · mol −1 (PPG2000) was cyclised with high conversion ( ca. 75%) by reaction with dichloromethane in the presence of powdered KOH. The cyclic product was separated from chain extended polymer by preparative GPC, giving an overall yield of polymer ( M̄ n ≈ 2000 g · mol −1 , narrow molar mass distribution) in excess of 50%. Characterisation by analytical GPC and 13 C NMR spectroscopy confirmed cyclisation. DEPT and 1 H‐coupled NMR spectra were used to show that the links in cyclic poly(oxypropylene) were 77% single acetal, 12% double acetal and 11% triple acetal (or higher). This complexity probably results from competitive reaction with water introduced with KOH.