Secondary reactions significantly affect acrylate polymerization rates as well as the architecture of polymer produced by high‐temperature solution radical polymerization. This impact is amplified under the semi‐batch starved‐feed policy used to keep monomer concentration low. Thus, the importance of intramolecular chain transfer (backbiting) is significantly increased, generating a tertiary radical center capable of termination, propagation, and scission. In this investigation, a comprehensive stochastic model is formulated to represent results from an experimental study designed to increase the fraction of reactive terminal double bonds (TDB) in the poly(butyl acrylate) product. Model predictions generated using three sets of literature kinetic parameters for backbiting and scission are compared. While each provides reasonable predictions of some reaction characteristics (e.g., free monomer levels, polymer molecular weights, polymer TDB content), none provide an adequate representation of all aspects of the polymerization. It is concluded that other reaction pathways might be needed to represent the system under semi‐batch conditions, thus explaining the discrepancies seen among the current parameter estimates.

Solution radical homopolymerization of isobornyl acrylate (iBoA) under starved‐feed higher temperature conditions unexpectedly leads to polymer product with low dispersity (<1.3) compared to the polymerization of butyl acrylate (BA) under identical conditions. Both backbiting and β‐scission reactions occur, as the poly(iBoA) product contains close to 100% terminal double bond (TDB) functionality. However, the addition of monomer to the midchain radicals formed by backbiting is sterically hindered, greatly reducing both short and long‐chain branching. The poly(iBoA) macromonomer functions as an excellent addition–fragmentation agent, not only lowering dispersity but also providing a means to efficiently produce blocky acrylate copolymers through sequential monomer feeding in the starved‐feed semibatch process.