Study On ATRP Synthesis Of Star Quaternary Ammonium Polymer

The basic idea of this dissertation is to synthesize star polymers by the atom transfer radical polymerization(ATRP)method,which is becoming increasingly a hotspot.(1)Synthesis of an initiator has multiple quaternary ammonium groups with the end group of C-Cl;(2)The plural ammonium salt synthesized by the first step is used as the initiator to polymerize the acrylamide as the polymerization monomer to produce a star polymer.Selecting hexamethylenetetramine with a steric structure and epichlorohydrin with both epoxy and C-Cl groups in the molecule as the raw material,through the N-alkylation reaction,four hexamethylenetetramine molecules Tertiary amine groups are converted to quaternary ammonium groups,while epichlorohydrin molecules undergo ring opening by epoxy cycloaddition(retaining C-Cl groups),ring-opening and subsequent ring closure of HCl(containing epoxy rings capable of forming C-Cl groups).Generates a star nucleus for atom transfer radical polymerization.The experimental results show that the optimal reaction conditions are as follows: at 45 °C in solvent water,take hexamethylenetetramine 0.04 mol,the molar ratio of hexamethylenetetramine to epichlorohydrin is 1:4,adjust the pH with lye For 9.5,the reaction was 2h and the epichlorohydrin conversion was 65.8%.The product had an epoxy value of 62.04% and a degree of hexamethylenetetramine substitution of 3.5.The structure of the product was identified by Fourier infrared spectroscopy,liquid chromatography and hydrogen nuclear magnetic spectrum.In the previous step,the star nuclear product was reacted with hydrochloric acid to open the epoxy ring to form a C-Cl bond.Three factors and three levels of orthogonal test were designed to analyze the extremely poor and other factors: the ring opening temperature was 40° C,the hydrochloric acid concentration was 0.4 ml/L,and the reaction time was 4 h.The ring-opened product was obtained and determined by IR spectra and elemental analysis.The ring-opening product contains chlorine groups and the structure is basically the same as expected.At the stage of polymerization,the commonly used monomer acrylamide(AM)and self-synthesized hexamethylenetetramine quaternary ammonium salt initiator were selected for ATRP reaction in aqueous solution.The effects of different factors single-rotation of ATRP and the activity control of ATRP were studied.(1)The ligand first forms a complex system with copper disodium edetate(EDTA).This system can control the free radicals in equilibrium,polymerization had certain controllability,but the conversion rate is slightly lower,and the ATRP linear correlation coefficient Show a linear relationship,only 0.93772;(2)Change the ligand,use ethylenediamine(en)/ Cu,in ω(AM)= 10%,n(CuCl): n(en)= 1,initiator,monomer With the complex ratio of 400:1:1,at the polymerization temperature of 65°C,a better monomer conversion rate of 73.08% was achieved,and the linear correlation coefficient of ATRP reached 0.99166.Under this condition,it has better controllability than the previous system.