Phenol formaldehyde resin, which is a kind of oligomer with relative molecular weight of 500-1000, is prepared by condensation polymerization of benzene and aldehydes in the presence of catalyst. It is the earliest industrialized synthetic resin, is also the first synthetic adhesive, or modified the first structural adhesive, first used in the aviation industry
The phenolic resin is of great polarity and has good adhesion to metals and most non metals, and the adhesive strength is higher. Due to the existence of a large number of benzene rings in phenolic resins, they can be cross-linked into a body structure, which has higher rigidity, high heat resistance, creep resistance, ablation resistance and good dimensional stability.
It has the advantages of water resistance, oil resistance, wear resistance, chemical resistance, mildew resistance, aging resistance and good electrical insulation performance. Itself is easy to modify, but also to other adhesives modified. In addition, it is brittle, low peel strength, shock resistance, vibration, the need for high temperature and high pressure curing for a long time, the shrinkage rate is greater, the color of the adhesive layer is deeper.
