The use of liquid chromatography for the characterization of novolac resins

Novolac resins made by condensation of phenol or p-cresol with formaldehyde in various mole ratios were analyzed by reversed-phase high-performance liquid chromatography (HPLC) and gel permeation chromatography (GPC). Number-average molecular weights (M_n) of phenol novolacs were determined by GPC and vapor-phase osmometry (VPO) and compared. A relationship was found between the content of dihydroxydiphenylmethane (DHDPM) and M_n of phenol novolacs. Attention was also paid to the quantitative determination of the content of phenol and DHDPM in the analyzed samples. The molecular characters of novolacs synthesized from phenol or p-cresol under the same conditions were compared. A relation was found between the molecular weight of phenol novolac and the tensile strength of abrasive material based on it. © 1993 John Wiley & Sons, Inc.