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Hydrolytic Polycondensation of Bisphenol‐A‐Bischloroformate Catalyzed by Phase‐Transfer Catalysts
Author(s) -
Kricheldorf Hans R.,
Böhme Sigrid,
Schwarz Gert,
Schultz ClausLudolf
Publication year - 2003
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200350028
Subject(s) - chemistry , catalysis , polycarbonate , bisphenol a , condensation polymer , bromide , polymer chemistry , hydrolysis , mass spectrum , molecular mass , phase transfer catalyst , phase (matter) , mass spectrometry , nuclear chemistry , organic chemistry , chromatography , epoxy , enzyme
The hydrolytic interfacial polycondensation of bisphenol‐A‐bischloroformate was performed with four different phase‐transfer (PT) catalysts: N ‐butylpyridinium bromide, triethylbenzylammonium (TEBA) chloride, tetrabutylammonium hydrogen sulfate, and tetraphenylphosphonium bromide. These polycondensations were conducted at 5 or 35 °C initial reaction temperature. The resulting polycarbonates were characterized by viscosity and SEC measurements and by MALDI‐TOF mass spectrometry. The four PT catalysts gave quite different results with respect to molecular weight and formation of cyclic polycarbonates. The highest molecular weights (number average, $\overline M _{\rm n} \approx 215\;{\rm kDa}$ and weight average, $\overline M _{\rm w} \approx 600\;{\rm kDa}$ ) were obtained with TEBA‐Cl. Lower temperatures and high feed ratios of TEBA‐Cl proved to be favorable for both high molecular weights and high fractions of cycles. Cyclic polycarbonates were detectable in the mass spectra up to 14 kDa (technical limit of the measurements). Low molecular weights in combination with unreacted chloroformate groups proved that the other PT‐catalysts were less efficient under the given reaction conditions.MALDI‐TOF mass spectrum of the polycarbonate No. 3b .