Synthesis And Recycling Of Two Novel Light-Sensitive Copolymers And Their Application In Aqueous Two-Phase Systems

ATPS (Aqueous two-phase systems) is a hopeful application technique in purification and bioconversion of bioproducts. However, high cost and environment pollution restrict its industrial application. In this dissertation, two novel light-sensitive and reversible water-soluble copolymers were synthesized and used in recycling ATPS. PNBAC was polymerized by using N-isopropylacrylamide (NIPA), n-butylmethacrylate (BMA), acrylic acid (AA) and chlorophyllin sodium copper salt (CHL) as monomers. Its average molecular weight (MW) was about 3.29×105. Another copolymer PNBAC was synthesized by NIPA, 2-(dimethylamino) ethylmethacrylate (DMAEMA), n-butyl methacrylate (BMA) and chlorophyllin sodium copper salt (CHL), and its MW is 5.4×104. The reaction yields of two copolymers are 66.9%and 77.2% or so. It can be calculated from the graph of 1H-NMR that the molar ratiosof monomers was 82:4:1:10 and 16:4:3:1 respcetively. The two copolymers could be recycled by light radiation. They showed reversible dissolution and could be precipitated by 488 nm laser irradiating with the least light density of 1.70×105W/m2. The precipitate energies of two copolymers are 1.71kJ and 3.81 kJ per gram, respectively.96.62% and 97.38% of two copolymers could be recovered by five-time from aqueous two-phase systems, respectively. The two copolymers can form aqueous two-phase systems. the best form phase condition is phase volume is 1:2, the top phase copolymer PNBAC is at 10%(w/w) and bottom phase copolymer PNDBC is at 10%(w/w), too.By applying the PNBAC-PNDBC aqueous two-phase systems to the separation of BSA and L-phenylalanine, the partition coefficient K of them could reach 2.1 and 0.52 in the systems, respectively. Specially, penicillin G can be extracted at the condition of pH is 5.5, two phases' concentration were 15%(w/w) and 10%(w/w) respectively. The best partition coefficient K is 4.25. When the copolymer PNDBC concentration is 8-12%(w/w) in ATPS, The relevance of the penicillin's partition coefficient with the concentration of polymer PNDBC was relatively well in the model lnK=0.3284(w"-w')+0.1239(w"-w')2+1.0503, (R2=0.9962).