CFD simulations of mixing conditions of isobutylene/maleic anhydride and their polymerization in continuous-flow synthesis

Abstract

Alternating copolymerization of isobutylene (IB) and maleic anhydride (MAh) affords valuable isobutylene–maleic anhydride (IBMA) materials. But conventional stirred-tank processes in ethyl acetate are hindered by heterogeneous gas–liquid–solid behavior, sluggish mass transfer, and product precipitation, while DMF, offering potential homogeneity, performs poorly under mild batch conditions. Here, we use CFD-guided reaction process design and a high-pressure continuous-flow strategy to convert the system into a single-phase, homogeneous operation in DMF by selecting an appropriate solvent/temperature/pressure window and enforcing rapid micromixing. This process-intensified approach delivers minute-scale residence times and an up to 85% yield at 100–130 °C and 3.3 MPa, with controllable M_n between 8 and 20 kg mol⁻¹ and narrow dispersity. By comparison, the ethyl acetate system required 4 h to reach an 84.9% yield, while batch in DMF at 70 °C and 0.5 MPa afforded only 2.66%. The method offers a route to otherwise intractable alternating copolymerization of gaseous monomers and precipitation products, with advantages in safety, productivity, and scalability.