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Determination of functionality and functionality distribution of polyether polyols by quantitative 13 C NMR spectroscopy
Author(s) -
Carr Robert H.,
Hernalsteen Jan,
Devos Julien
Publication year - 1994
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1994.070520802
Subject(s) - pentaerythritol , trimethylolpropane , propylene oxide , relaxation (psychology) , moiety , reagent , chemistry , ethylene oxide , carbon 13 nmr , glycerol , polymer chemistry , materials science , copolymer , analytical chemistry (journal) , organic chemistry , polyurethane , polymer , psychology , social psychology , fire retardant
A method is described for the determination of the number average functionality and functionality distribution of polyols based on the measured intensities of relevant end groups observed in 13 C NMR spectra. Longitudinal (T1) relaxation time measurements on glycerol‐, trimethylolpropane‐, and pentaerythritol‐initiated copolymers of propylene oxide and ethylene oxide show that the slowest relaxing moiety that needs to be quantified is the vinyl CH 2 group of the unsaturated side product of the propoxylation reaction. A. chromium (III)‐containing relaxation reagent allows the analysis to be speeded up by decreasing the relaxation times. The relative precision of the functionality measurement is ca. ±1%, while determinations of the mole percentage levels of species with different functionalities can be carried out with a precision better than ±3 mol %. © 1994 John Wiley & Sons, Inc.