A detailed mathematical model is developed to describe the solution copolymerization of acrylic acid (AA) and vinyl acetate (VA) in batch and continuous stirred tank reactors. Lacking kinetic parameters are then estimated, based on batch experimental data. To validate the model, experiments are carried out in continuous reactors, showing that model predictions are good in all conditions analysed. The model is then used to design operation conditions where AA/VA copolymers with uniform composition can be produced with small average AA block sizes.