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Evaluation of isomeric composition of resol‐type phenol formaldehyde matrix resins for silica–phenolic composites and its effect on cure characteristics of the resin
Author(s) -
Scariah K. J.,
Usha K. M.,
Narayanaswamy K.,
Shanmugam K.,
Sastri K. S.
Publication year - 2003
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.12918
Subject(s) - phenol , formaldehyde , curing (chemistry) , materials science , phenol formaldehyde resin , fourier transform infrared spectroscopy , hydroxymethyl , activation energy , kinetics , composite material , polymer chemistry , chemistry , chemical engineering , organic chemistry , physics , quantum mechanics , engineering
Abstract The isomeric composition of several samples of resol‐type phenol formaldehyde resins used for silica–phenolic composites was evaluated by 1 H‐ and 13 C‐NMR spectroscopy and reverse‐phase HPLC techniques. The variations in the isomeric compositions were attributed to inadvertent variations in the process parameters. A mathematical relation was determined for calculation of free phenol from 1 H‐NMR measurements. The samples were cured at 160°C for 8 h in an inert atmosphere of N 2 . The extent of cure in the hardened samples was measured by FTIR analysis. The effect of isomeric composition on the extent of cure was studied. Free phenol and p ‐hydroxymethyl phenol, exhibiting a linear correlation, were found to have a pronounced effect on the extent of cure. The cure kinetics were derived by dynamic DSC measurements. Activation energy ( E ) for curing exhibited a near linear correlation independently with free phenol content and the extent of cure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2517–2524, 2003