Reactivity Ratios of Biobased Dibutyl Itaconate with Conventional and Renewable (Meth)Acrylates: Influence of Depropagation

The global push for sustainability has driven interest in renewable monomers such as dibutyl itaconate (DBI). Despite its potential for biobased high-performance polymers, DBI's copolymerization with (meth)acrylates is challenging due to low propagation rates, depropagation at moderate temperatures, and unfavorable reactivity ratios. This study investigates the solution copolymerization of DBI with both conventional, butyl acrylate (BA) and methyl methacrylate (MMA), and biobased (2-octyl acrylate (2-OA) and isobornyl acrylate (IBOA)) monomers. Using in situ ¹H NMR and nonlinear least-squares fitting, reactivity ratios were determined: BA/DBI (<i>r</i>_BA = 0.68, <i>r</i>_DBI = 0.68), MMA/DBI (<i>r</i>_MMA = 3.53, <i>r</i>_DBI = 0.38), 2-OA/DBI (<i>r</i>_2-OA = 1.64, <i>r</i>_DBI = 1.44), and IBOA/DBI (<i>r</i>_IBOA = 1.87, <i>r</i>_DBI = 2.0). The study also clarifies discrepancies in literature values for BA/DBI due to uncertainties in DBI's depropagation rates. DBI copolymers with BA, 2-OA, and IBOA showed a lower composition drift than MMA/DBI, which showed a greater disparity in reactivity ratios.