Synthesis of water-soluble phenolic resin as crosslinker of polymer weak gel

A study was carried out on the technology of synthesizing water soluble phenol-formaldehyde resin (PFR) as crosslinker for weak polymer gels (WPG). The PFR prepared in two-step alkaline catalyzed polycondensation contained much less free formaldehyde and possessed much higher hydroxymethyl content, thus was superior to the one-step polycondensation product. For PFR of two-step technology, the viscosity increased continuously with increasing F/P molar ratio and all the relationships of HMC and of WPG viscosity. The optimum parameters of synthesis of PFR as crosslinker for WPG were obtained.