Synthesis Of Two Novel Thermo-Sensitive Copolymers Forming Aqueous Two-phase Systems And Their Application

Aqueous two-phase systems (ATPS) is a promising separation technology in the purification of biomaterials. However, the non-recovery of the polymers leading to high costs and environmental pollution has become the great obstacle to scale-up in the industry. In this work, two novel thermo-sensitive copolymers that can form ATPS were synthesized. PNBAa was copolymerized by using N-isopropylacrylamide (NIPA), methacrylate(BMA), Allyl alcohol (Aa) as monomers, while copolymer PNDB was copolymerized with N-isopropylacrylamide (NIPA),2-(dimethylamino)ethyl methacrylate (DMAEMA) and methacrylate(BMA) as monomers. Both of the two polymers are thermo-sensitive, and can be recycled by increasing the temperature, the recovery rate can reach up to above 97%. The application work was carried out on the partition of Demeclocycline, the partition coefficient K could reach 2.21.The recyclable aqueous two-phase systems formed by thermo-sensitive polymer (PNB) and pH-sensitive polymer (PADB) have been prepared by our laboratory. In this study, the Flory-Huggins model derived from the lattice theories and the COVE model based on the McMillan-Mayer solution theory were used for correlations and predictions of phase diagrams. The interaction parameters between the solvent and the polymers of the Flory-Huggins model were calculated from solubility parameters. The interaction parameters between the polymers and the COVE coefficients were determined by fitting experimental data. Simulation of Flory-Huggins model and COVE model indicates that the deviation between prediction values and experimental data is less than 0.50%. The COVE model was more effective than the Flory-Huggins model to this system.