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Controlled Polymerization Of ATRP By Using Ni2+/3+ Complex In Water Phase

Posted on:2016-01-20Degree:MasterType:Thesis
Country:ChinaCandidate:J LiuFull Text:PDF
GTID:2271330470960543Subject:Chemical Engineering and Technology
Abstract/Summary:PDF Full Text Request
In the presence of nickel complex, acrylamide in an aqueous solution about atom transfer radical polymerization was studied. Nickel complex and potassium persulfate occured redox reaction, and generated free radicals and the oxidation state of the nickel complexes.Both established a dynamic reversible equilibrium and control the concentration of free radicals. nickel complex plays a dual role.The molecular weight of the polymer to improve gradually with increasing the conversion rate increases,the molecular weight of the polymer to improve gradually with increasing the conversion rate.The linear correlation coefficient of polymerization kinetics was good, showing characteristics of atom transfer free radical polymerization.Polymerization of acrylamide polymerization in aqueous solutionfor was studied, the first to ethylenediamine(en) as ligand,when nickel amine complex[Ni Cl2 / en] was join, it can effectively reduce the initiation process of activation energy,and the reaction can be at room temperature,and the polymerization process is completed in a short time.When n(Ni2+):n(en)=1:2,rate of initiation was the fastest;When n(Ni2+):n(en)=1:1,linear correlation coefficient was the best.When c(KPS)=0.129mmol/L,c[Ni Cl2/en]=0.129mmol/L,n(Ni2+):n(en)=1:1,linear correlation coefficient reached 0.941 and the molecular weight was4.04×106.The atom transfer radical at room temperature reaction was realized,indicating that the nickel amine complex ions in the aqueous solution was a excellent performance catalyst on atom transfer radical polymerization. The system was complex of EDTA and nickel and the comlex has good reductive.When c(Ni Cl2 / EDTA) = 2.253 mmol / L, c(KPS) = 1.567 mmol / L, n(Ni2+): n(EDTA)=1:1.1,the polymerization temperature T = 35℃, polymerization reaction is best controlled in 7 hours.Polymerization of acrylamide polymerization in aqueous solutionfor wasstudied,en and EDTA as ligands.When w(AM)=10%,n(Ni2+):n(EDTA/en)=1:1,n(EDTA):n(en)=1:1,c(KPS)=3.521mmol/L,c(complex)=4.499mmol/L,temper ature T=30℃, linear correlation coefficient reached 0.99153,indicating that t he systems are controllable and has the characteristics of atom transfer radical polymerization.The molecular weight of PAM is increased with the conversion of AM. The molecular weight of PAM was more than 10 milli on belong to the ultra-high molecular weight PAM.
Keywords/Search Tags:atom transfer radical polymerization, Ni(en)x2+, Ni(EDTA)2-, Acrylamide
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