POLYMER-SOLUTION PROPERTIES OF A PHENOL FORMALDEHYDE RESOL RESIN BY GEL-PERMEATION CHROMATOGRAPHY, INTRINSIC-VISCOSITY, STATIC LIGHT-SCATTERING, AND VAPOR-PRESSURE OSMOMETRIC METHODS

A plywood adhesive-type phenol-formaldehyde (PF) resol resin was shown to have structures generally described as polymeric methylene (hydroxymethyl)phenols as determined by C-13 NMR, and static light scattering gave molecular weights of up to about 114000 daltons. The molecular weight and intrinsic viscosity data resulted in a Mark-Houwink exponent of 0.21 in tetrahydrofuran and 0.15 in ethyl acetate, which indicated a compact molecular structure in solution due to branching of the polymer chain. With the molecular weight and intrinsic viscosity data, the gel permeation chromatographic results obtained on a cross-linked polystyrene gel in tetrahydrofuran gave a universal calibration curve that agreed well with a similar curve obtained for linear polystyrene standards. This work determined the molecular weight and extent of branching of a wood adhesive PF resol resin synthesized by sodium hydroxide catalysis.