Curing of phenolic-based compositions

Processing of phenol-aldehyde oligomers into various articles is based on a polycondensation reaction which leads to solidification of the material at temperatures below 200°C and pressures exceeding 10 MPa. The process is accompanied by volatile product formation. However, phenol-formaldehyde resins of the resol type can be cast without additional pressure and heat. The raw molding reactants contain different organic and mineral fillers and other additives in addition to the basic resin. 

The strength of articles based on phenolic compositions and solidified without additional pressure and heat supply is 2-4 times lower than the strength of thermally solidified resins this limits their applications as engineering materials. One of the primary causes of material strength decrease is pore formation due to volatilization of water and formaldehyde during polycondensation. Different water adsorbents (calcium carbonate, clay, silicates, methasilicates, zeolites, etc.) should be 

Component Contents, weight proportions Curing temperature, °C Type Main fields of application 

Dian resin, modified by aliphatic epoxy resin 100 140-150 binder Binder for reinforced plastics 

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