The Investigation Of Diethylenetriamine And Its Derivatives Effect On ATRP

The thesis contains three parts that research the effect of diethylenetriamine and its derivatives on atom transfer radical polymerization:1. AGET ATRP of methyl methacrylate with PMDETA or MA₅-DETA as reducing agentActivator generated by electron transfer atom transfer radical polymerization of methyl methacrylate (MMA) with air-stable Cu(II)X₂(X=Br, Cl) as the catalyst and PMDETA or MA₅-DETA as both ligand and reducing agent was investigated. Well-controlled PMMA with low PDI was prepared in the presence of Cu(II) and nitrogen-based ligands without any additional reducing agent. The molecular weight distribution of the resulting polymer was rather narrow (M_w/M_n =1.10-1.20) and the system showed good controllability. Chain extension of PMMA with MMA was successful, resulting in low-PDI PMMA and demonstrating well-maintained end-group functionality.By contrast to the blank assay, we found methyl methacrylate will not polymerize or be in a slowly reaction rate in the absence of Cu(II), initiator or ligand. Nitrogen-based ligands can serve as reducing agents, reduce Cu(II) to Cu(I) for AGET ATRP, as well as ligands. Effects of the PMDETA and MA₅-DETA content and the catalysts on polymerization were also investigated, respectively. 2. AGET ATRP of methyl methacrylate in the presence of oxygenThe normal atom transfer radical polymerization needs an anhydrous and oxygen free condition. When polymerization catalyzed by CuCl/MA₃-DETA, Well-controlled poly (methyl methacrylate) was prepared in the presence of oxygen. By contrast to the resulting polymer in the oxygen free condition, the molecular weight and polydispersity had no changes much. Chain extension of PMMA with MMA was successful, resulting in low-PDI PMMA and demonstrating well-maintained end-group functionality.AGET ATRP of MMA with Cu(â…¡) as catalyst, PMDETA or MA₅-DETA as ligand and diethylenetriamine as reducing agent. The molecular weight distribution of the resulting polymer was rather narrow (PDI=1.24), and the dynamics research and chain extension reaction indicated the CuX₂/PMDETA/DETA/Initiator system is a living radical polymerization.3. The effect of diethylenetriamine and its derivatives as additives on ATRP Considering DETA has five living H and the MA₅-DETA is a good ligand, the effect of ligand with different number of living H on ATRP is studied. It is found that the polymerization is greatly effected by ligands (MAn-DETA) with different number of living H. A system with MA₃-DETA as ligand processed the fastest reaction rete; the other one with MA₅-DETA as ligand showed the best controllability.When DETA, MA₃-DETA and PMDETA was added in the normal ATRP before reaction, the resulting polymer molecular weight and polydispersity will have big changes; When DETA and MA₃-DETA is added into the polymerization system in the reaction period, the molecular weight of the resulting polymer will increase in different degrees. The polydispersity of the resulting polymer with DETA had a big change. The comparison among 1H-NMR of the resulting polymers indicated the polymer did not react with additives, the reason of acceleration was the additives reduced Cu(II) to Cu(I), then caused radical concentration had a instantaneous increase.