Graphical A universal high reactive ligand, Me 6 TREN, was successfully explored as the reducing agent for the ambient temperature copper-mediated LRP of AN. The key to success is ascribed to the optimized Me 6 TREN amount and reaction conditions employed, producing ideal living free radical polymerization characteristics. The very high chain-end functionality of the resultant polymer has been confirmed by GPC and 1 H NMR analyses as well as the chain-extension reaction.
A universal nitrogen based ligand, tris[2-(dimethylamino) ethyl] amine (Me 6 TREN), was firstly employed as both reducing agent and ligand for atom transfer radical polymerization with activators regenerated by electron transfer (ARGET ATRP) of methyl methacrylate (MMA) in bulk and solution, using CuBr 2 as the catalyst and 2-bromoisobutyrate as the initiator. Remarkably high activity catalytic system (CuBr 2 /Me 6 TREN) enabled the ambient temperature polymerization and thus biradical termination reactions were low. The polymerization exhibited typical living radical polymerization features, including pseudo first-order kinetics of polymerization, linear increase in the molecular weight versus monomer conversion, and low polydispersity index values. Moreover, effects of solvent and reaction temperature on the polymerization were investigated in detail. The rate of polymerization increased with reaction temperature and the apparent activation energy of the polymerization was calculated to be 51.11 kJ/mol. Gel permeation chromatography and 1 H NMR analyses as well as chain extension experiment confirmed the living chain-end functionality.
Controlled radical polymerization (CRP) under external field has been an attractive research area in these years. In this work, a new electron transfer mechanism, that is, sonochemically induced electron transfer (SET) was introduced to mediate polymerization for the first time. The activator Cu I X/L complex was (re)generated from Cu II X 2 /L in dimethylsulfoxide (DMSO) by the SET process in the presence of free ligand tris(2-dimethylaminoethyl)amine (Me 6 TREN). The investigation of polymerization including the mechanistic insights and effect of experimental conditions on the rate of reaction has been undertaken. Kinetics of Cu(II)-catalyzed CRPs via SET under different conditions (i.e., Me 6 TREN concentration, catalyst loading, targeted degree of polymerization, and sonication power) were conducted in an unprecedentedly controlled manner, yielding polymers with predetermined molar masses and low dispersities ( Đ < 1.12). Attractively, the polymerization can be performed without the piezoelectric nanoparticles and exogenous reducing agent. Contamination by nonliving chains formed from sonochemically generated radicals is avoided as well. All of these results supported that Cu(II)-based catalyst activation enabled by ultrasonication has a promising potential in scale-up of CRP.
危险品化学品经营许可证（带存储）