Modelling and control of the microstructure of comb-like poly(MAA-co-PEGMA) water-soluble copolymers†
Water-soluble copolymers of methacrylic acid and poly(ethylene glycol) methacrylate (poly(MAA-co-PEGMA)) present a comb like structure. These macromolecules under alkaline conditions present an anionic backbone and uncharged side chains. The control of their microstructure is of paramount importance for application as cementitious admixtures. With this in mind, open-loop control strategies including monomer starved and optimal addition policies were employed to obtain homogeneous composition copolymers. A detailed mathematical model was developed for the copolymerization of MAA and PEGMA5 and was used to develop optimal feeding strategies. The mathematical model provides a good representation of the experimental data sets and copolymers with desired homogeneous copolymer compositions were synthesized within the shortest possible reaction times.