Deterministic Modeling of Degenerative RAFT Miniemulsion Polymerization Rate and Average Polymer Characteristics: Invalidity of Zero–One Nature at Higher Monomer Conversions

Abstract

The polymerization rate and average polymer characteristics of degenerative reversible addition–fragmentation chain transfer (RAFT) miniemulsion polymerization of methyl methacrylate with cyanoprop-2-yl dithiobenzoate as initial RAFT agent (R0X) and potassium persulfate as initiator are studied at 333 K up to monomer conversions of 95%, considering a two-dimensional Smith–Ewart model. This model accounts for the number of macroradicals and R0 radicals per nanoparticle, an average particle size between 50 and 500 nm, targeted chain lengths (TCLs) between 50 and 600, exit/entry of R0 radicals, and the possible influence of diffusional limitations on termination and RAFT transfer at the microscale. The accuracy of the microscale model parameters is highlighted by a successful description of bulk literature data, and the interphase mesoscale parameters are determined based on literature miniemulsion data at various average particle sizes. It is demonstrated that at high monomer conversions it is not afforded ...