Preparation Of Hydrophobically Modified Pam By Irradiation Grafting

Hydrophobically associating polymer has good resistance to temperature, salt resistance and shear resistance, thus it has become the dominant development trend of chemical displacing agent for the future. In order to obtain high molecular weight, high yield, low cost, easy-to-industrial production, we turn to radiation grafting technique to hydrophobically modify PAM, that is, to synthesize hydrophobic polyacrylamide by introducing a small amount of hydrophobic groups into PAM main chain.This study employs pre-irradiation grafting copolymerization and mutual radiation grafting copolymerization to synthesize hydrophobically modified polyacrylamide, which was characterized by IR. The experimental result demonstrates that, PAM is irradiation-crosslinkable polymer, which plays a dominant role in the radiation process of ⁶⁰Co-γray. In the pre-irradiation grafting copolymerization, two copolymerization process are used, namely, pre-irradiation grafting of PAM with solution copolymerization and pre-irradiation grafting of PAM with micellar copolymerization. In the pre-irradiation grafting of PAM with micellar copolymerization, the effects of hydrophobic monomer concentration, pH, water-soluble comonomer concentration, irradiation time, reaction time and temperature which affect the apparent viscosity of grafting product on the apparent viscosity of grafting product was discussed. A suitable reaction conditions were determined. Compared with PAM, the grafted products of these two processes have certain thickening effect. And the latter process shows great advantage over the former one for its higher apparent viscosity.In mutual radiation grafting copolymerization, mutual radiation grafting of PAM in swelling state and mutual radiation grafting of PAM in solid phase are used. These two processes can modify PAM hydrophobically to a certain extent. Compared to the latter, the former process brings on serious irradiation-crosslinking of the grafting products when the radiation dose is more than 0.3kGy, which affects water-solubility.