Fabrication of the weak gel based on hydrolyzed polyacrylamide crosslinked by inorganic-organic mixed crosslinker

摘要

A novel weak gel of hydrolyzed polyacrylamide (HPAM) was prepared using inorganic–organic mixed crosslinker. The inorganic crosslinker was aluminum citrate (AlCit), and the organic crosslinker was 1,3,4,6-tetrahydroxymethylglycoluril (TMGU). The viscosity measurements showed that the viscosity of HPAM solutions was effectively increased from 80 mPas to 2500 mPas in stable state when 130 mg L~(-1) AlCit and 600 mg L~(-1) TMGU were added, and the gelation time of the weak gel could also bewell controlled by changing the concentration of AlCit. Scanning electron microscope showed the formation of crosslinking structure of HPAM crosslinked by AlCit and the interpenetrating polymer network of weak gel crosslinked by AlCit and TMGU mixed crosslinker. Viscoelastic measurements indicted the elastic nature of weak gel. Fourier transform infrared spectra indicted that the carboxyl group of HPAM worked with AlCit while the amide group of HPAM worked with TMGU in the formation of weak gel. Thermogravimetric analyses and viscosity measurement indicted that AlCit may play the major role in the formation of weak gel. The mechanism of the formation of the weak gel was also discussed. The weak gel fabricated with high viscosity may have potential use in oil recovery due to its high viscosity.