1 This International Standard specifies chromato-graphic methods for the separation of phenolic resins into their component compounds. Separation takes place according to molecular weight and/or polarity.
There are various liquid chromatographic methods:
A: Gel-permeation chromatography
B: High-performance liquid chromatography on polar columns
C: High-performance liquid chromatography on non-polar columns
It is possible to separate a phenolic resin into its components according to molecular size using method A (gel-permeation chromatography). Whereas free phenol and the sum of the dihydro-xydiphenylmethanes (in novolaks) and various methylolphenols (in resols) are quantitatively separ-ated in this procedure, high-molecular-weight compo-nents of the resins are only incompletely separated due to the multitude of isomers.
Methods B and C (high-performance liquid chroma-tography) separate the compounds in the resin ac-cording to molecular weight and polarity. Molecular-weight effects predominate on polar sta-tionary phases (method B), and the effect of polarity on non-polar stationary phases (method C). These methods also allow quantitative determination of in-dividual low-molecular-weight resin components. Be-cause of the different resin solubilities, method B is more suitable for novolaks and method C for resols.
2 The methods are applicable to phenolic resins that are soluble in the solvents and solvent blends used.
3 This test is useful for characterization of pro-ducts and for research.
BS EN ISO 11401:1998 history
1998BS EN ISO 11401:1998 Plastics - Phenolic resins - Separation by liquid chromatography