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Shelf life of phenolic resole resins
Author(s) -
Gupta Manoj K.,
Hindersinn Raymond R.
Publication year - 1987
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760271308
Subject(s) - gel permeation chromatography , viscosity , carbon fibers , materials science , molar mass distribution , carbon 13 nmr , molecular mass , intrinsic viscosity , organic chemistry , polymer chemistry , chemistry , polymer , composite material , composite number , enzyme
Abstract Viscosity, number‐average and weight‐average molecular weights (measured by gel permeation chromatography), and carbon‐13 nuclear magnetic resonance (NMR) were used to monitor the changes in phenolic resoles as a function of time and pH. It was observed that phenolic resoles with pH around 5 are more stable, as indicated by the lowest increase in viscosity and molecular weight. Carbon‐13 NMR spectroscopic studies also suggest that the concentration of methylol groups is higher for resoles with pH around 5 and, thereby, indicate a slower reaction.