Studies On The Synthesis Of Star-shaped Water-soluble Acrylamide Polymers Via SET-LRP

Star polymer,as a non-linear structural polymer,consists of core and multiple linear branches radiated from the core.Due to its unique structure,it has a smaller hydrodynamic volume than linear polymers and the molecules should not be tangled,and the function of the functional group in the molecule can be expressed more completely.In this paper,Star-shaped water-soluble acrylamide polymers with functions of temperature resistance and salt resistance were synthsized by a relatively new polymerization method,which was called Single Electron Transfer Living Radical Polymerization(SET-LRP)?1.The tris(2-dimethylaminoethy)amine was synthesized by using tris(2-aminoethyl)amine,formaldehyde and methanoic acid as the monomers.Using pentaerythritol and 2-bromoisobutyryl bromide as raw materials and triethylamine as acid-binding agent,a star macro-initiator pentaerythritol 2-bromoisobutyrate(PT-Br)was synthesized in tetrahydrofuran.1,2,3,4,6-penta-O-isobutyryl bromide-a-D-glucose(Glc-Br)was synthesized by glucose and 2-bromoisobutyryl bromide in pyridine and chloroform mixed solvents.thouse products was confirmed to be the target product by FT-IR and 1H-NMR and have a high purity.2.The star-shaped polymers which P(AM-co-Nt BA)and P(AM-co-Na AMPS)was synthesized by SET-LRP in aqueous solution,with PT-Br as the initiator and initial Cu0 obtained by in situ disproportionation and CuIIX2/ Me6-TREN as catalytic system.The starshaped polymers which P(AM-co-NVP)was synthesized by SET-LRP in Mixed solvent of water and ethanol,with Glc-Br as the multifunctional initiator and initial Cu0 obtained by in situ disproportionation and CuIIX2/ Me6-TREN as catalytic system.The effects of reaction time,amount of initiator,amount of Cu Br,and monomer concentration on the polymerization reaction were investigated,and the optimum process conditions for the polymerization reaction were determined.Four-arm star polymer which P(AM-co-Nt BA)with a maximum viscosity average molecular weight of 69,400,four-arm star polymer which P(AM-co-Na AMPS)with a viscosity average molecular weight of 72000,five-arm star polymer which P(AM-coNa AMPS)with a viscosity average molecular weight of 77400 was synthesized and the product was confirmed to be the target product and the chain end retains the-Br end group by FT-IR and 1H-NMR.3.The temperature-resistance and salt-resistance of three star-type water-soluble acrylamide polymers were studied.With the increase of temperature and increase of salt concentration,the apparent viscosity retention rate of star-type water-soluble acrylamide polymer solution was higher than the corresponding Molecular weight hydrolyzed polyacrylamide...