Preparation and properties of glycol- and polyetherol-modified phenol-formaldehyde resins
Polimery 2000, No 10, 687
SummaryPhenol-formaldehyde resols were modified with di- and. tri-functional Rokopol-type polyetherols (Table 1) and with selected glycols: 1,2-ethanediol, 2,2-oxydiethanol or 1,4-butanediol. Modification conditions for, and physicochemical property data on the resulting resins were determined (Tables 3, 4) and IR spectra (Figs. 1, 2) were recorded to characterize the structure of the resins. In the modified resols, dry weight and free monomer contents were found to be respectively high and low. Varnish coatings were prepared from the modified resins. The coatings exhibited a very good adhesion to the substrate; their elasticity, impact strength and hardness were related to the modifier nature (Tables 5, 6). Difunctional polyetherols (e.g., Rokopol D2002) were best modifiers. The modified resins showed a high thermal resistance (Table 7) in terms of TGA data.