Fractionation and characterization of phenolic resins by high-performance liquid chromatography and gel-permeation chromatography combined with ultraviolet, refractive index, mass spectrometry and light-scattering detection.

HPLC and gel permeation chromatographic (GPC) characterization of complex phenol-formaldehyde resins is described. Reversed-phase HPLC fingerprints the phenolic monomers, dimers and some oligomers. The molecular masses of these phenolic compounds were determined using an ion trap mass spectrometer. GPC analyzes tetrahydrofuran-soluble phenolic polymers beyond HPLC capability. The molecular mass distribution and structural information of the phenolics was determined by both conventional and laser light-scattering calibration methods. GPC with both UV and refractive index detection provides weight concentration of phenolic resin and the molar concentration of the phenol unit in the oligomers or polymers.