Study On ATRP Polymerization Of Acrylamide In Co-Complex/Terminal C-Br System

In this paper,the ATRP polymerization of acrylamide in the Co-complex/terminal C-Br system was studied.The self-made poly-quaternary ammonium salt of terminal C-Br was used as the initiator,and ethylenediamine and cobalt chloride were formed.The Co-complex serves as a catalytic system that initiates the ATRP reaction of acrylamide.The details are as follows:1?Preparation of Polyquaternium Initiator:Used tetramethylethylenediamine and 1,2-dibromoethane as raw materials,synthesis of poly-quaternium with high-charge-density as the main chain segment with terminal group C-Br by precipitation polymerization.By investigating the influence of different reaction conditions on the reaction conversion rate and the relative molecular mass of polyquaternium,the optimal synthesis conditions were obtained:n-propanol as the solvent,the molar ratio of tetramethylethylenediamine and 1,2-dibromoethane was 1:2,the concentration of tetramethylethylenediamine was 0.50 mol/L,the temperature was70?,and the reaction was 8 h,the conversion rate of tetramethylethylenediamine was 52.0%.The ammonium salt had a relative molecular weight of 3,500.Through the determination of the C-Br bond content of the end group,the existence of the terminal C-Br bond was verified;the product was analyzed by nuclear magnetic spectrum,the structure of the product was in line with expectations;the elemental analysis of the product,the content of each element and the theoretical value Consistent;the product did not decompose below 250?and had good thermal stability.2?In the Co-complex catalytic system,an ATRP reaction of acrylamide was performed.Firstly,the experimental analysis of polyacrylamide gel and polyacrylamide gel permeation chromatograms after polymerization shows that polyquaternium can initiate the polymerization of acrylamide;then it explores the different polymerization conditions for monomer conversion.The effects of the polymerization and the controllability of the polymerization resulted in the following conclusions:Polymerization in the aqueous phase,the mass fraction of acrylamide was 10%,a self-made polyquaternium was used as an initiator,and cobalt chloride and ethylenediamine were formed in a ratio of 1:2.The Co-complex was a catalytic system,at 80°C,the reaction time was 12 h,the monomer conversion rate was 69.8%,the viscosity average molecular weight of the polymer was 5.2×10~4,and the linear correlation coefficient of the polymerization kinetic curve was 0.8570.