QUANTITATIVE C-13 SOLID-STATE NMR AND FT-RAMAN SPECTROSCOPY IN NOVOLAC RESINS

A qualitative and quantitative study of the curing behaviour of a high -ortho novolac resin with paraformaldehyde under different conditions is reported. The extent of cure by means of the formaldehyde/phenol ra tio, the degree of conversion, and the characterization of the final s tructure after curing are determined based on quantitative C-13 solid- state nuclear magnetic resonance with cross polarization and magic ang le spinning. The T-1H relaxation time is measured as a probe to follow the evolution of cure. In conjunction Fourier transform-Raman spectro scopy is proposed as a qualitative tool to follow the degree of crossl inking in this high-ortho novolac. (C) 1998 Elsevier Science Ltd. All rights reserved.