Analysis of Phenol-formaldehyde Resins by GPC and Agilent PolarGel-M

Phenol formaldehyde (P-F) resins are thermoplastic materials made with an excess
of phenol in an acid catalyzed reaction with formaldehyde. P-F resins are commonly
used as precursors to varnishes and other surface finish products.
GPC Analysis
PolarGel-M GPC columns are packed with low swell,
macroporous copolymer beads that have a surface of
balanced polarity, comprizing hydrophobic and hydrophilic
components. These allow PolarGel-M to be used in the
analysis of high polarity polymers that are insoluble in water
to give a more accurate representation of the molecular
weight distribution of the polymer. If these polar polymers
were to be analyzed with traditional styrene/divinyl benzene
columns, interactions would cause artifacts in the peak
shape and longer retention times, which would translate into
apparently much lower molecular weight averages.
Sample Preparation
Two types of phenol-formaldehyde resin were analyzed to
obtain an indication of differences in molecular weight, if
any. The samples were made up in 0.2 % (w/v) DMF, with
0.1 % LiBr added to reduce sample aggregation, and injected
without further treatment.

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