ARGET ATRP of Butyl Methacrylate: Utilizing Kinetic Modeling To Understand Experimental Trends

Abstract

A comprehensive kinetic Monte Carlo (kMC) model is used to interpret and better understand the results of a systematic experimental investigation of activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) of butyl methacrylate (BMA) using Sn(EH) 2 as reducing agent, ethyl 2-bromoisobutyrate (EBiB) as ATRP initiator, and CuBr 2 /TPMA (TPMA: tris[(2-pyridyl)methyl]amine) as deactivator. The model demonstrates the importance of slow initiation, with distinct activation and deactivation rate coefficients for the initiator and polymeric species required to match the experimental data. In addition, the model incorporates a second reduction step for the reducing agent and accounts for diffusional limitations on chainlength-dependent termination. The effect of temperature on the slow ATRP initiation is limited, and a sufficiently high initial reducing agent concentration is crucial to obtain a high conversion, although achieved at the expense of decreased end-group functionality.

Modeling the Influence of Diffusion-Controlled Reactions and Residual Termination and Deactivation on the Rate and Control of Bulk ATRP at High Conversions

“…Furthermore, the deactivation rate coefficient is typically much higher than that of activation. A faster reaction becomes diffusion controlled earlier than a slower one, which is evident from Equation 22. Figure 2 shows the influence of diffusion-controlled deactivation with or without residual deactivation on the rate and control of polymerization, in the presence of diffusion-controlled termination (k , = 10 14 ) and residual termination (ztde = 100 & ztp = 10).…”

Exploring the Full Potential of Reversible Deactivation Radical Polymerization Using Pareto-Optimal Fronts

“…In this work, for the first time, the potential of MOO for RDRP will be illustrated, considering ARGET ATRP of butyl methacrylate (BMA) and NMP of styrene as model cases and using NSGA-II [61][62][63]. All kinetic and diffusion parameters are taken from literature [61,64,65] and a variety of optimization paths, such as temperature and fed-batch addition programs, are included, considering time, Ð and EGF as objectives. For simplicity, the objectives are evaluated only at a final conversion of 0.75.…”

Fed-Batch Control and Visualization of Monomer Sequences of Individual ICAR ATRP Gradient Copolymer Chains

“…With these modified techniques, an ATRP catalyst level of ca. 50 ppm could be obtained increasing the industrial potential of the ATRP technique [11].…”

“…During the last decades, the design of well-tailored polymers molecules with predetermined number average chain length, high end-group functionality (EGF), controlled topology and low dispersity has been the topic of many research activities [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These advanced macromolecular architectures are typically acquired via controlled radical polymerization (CRP), which is also known as reversible deactivation radical polymerization (RDRP).…”

“…Additionally, the activator is oxygen sensitive implying stringent experimental procedures with respect to oxygen removal and the high ATRP catalyst amounts lead to intensive purification processes. Hence, more recently modified ATRP techniques have been developed in which a low ATRP catalyst amount is used and activator is (re)generated from the oxygen insensitive deactivator through an external source, e.g., an electrode or a reducing agent) [11,[16][17][18][19][20][21]. With these modified techniques, an ATRP catalyst level of ca.…”