2020/07/30 by Luca Banetta, Banetta, Luca, Giuseppe Storti +7
Chemistry · Materials Science · #Advanced Polymer Synthesis and Characterization #Photopolymerization techniques and applications #Polymer Science and PVC
paper · pdf · doi:10.48550/arxiv.2007.15509
A mathematical model to describe the emulsion polymerization kinetics of co-\nand ter-polymerizations is developed. The model is based on the classical\nSmith-Ewart (SE) equations, within the pseudo-homopolymerization approach, with\nstate-of-the-art models for radical entry and desorption. For co- and\nter-polymerizations there are unknown parameters in the model which are related\nto monomer-specific gel-effect coefficients, that are needed to compute the\nbimolecular termination reaction rates. The unknown parameters are determined\nthrough extensive calibration of the model on literature data for homo- and\nco-polymerizations of \n-butyl acrylate (n-BA) and methyl methacrylate\n(MMA). The so-obtained predictive model is then applied to the modelling of the\nter-polymerization of n-BA and MMA with 2-hydroxyethyl methacrylate (2-HEMA)\nwith sodium persulphate (SPR) as initiator: predictions for the time-evolution\nof particle size and conversion are in excellent agreement with experimental\nmeasurements using Dynamic Light Scattering (DLS) and Gas Chromatography (GC),\nupon tuning the gel-effect coefficient related to 2-HEMA. The developed model\nis used to quantify the surfactant surface coverage of the particles as well as\nthe total concentration of counterions in the system throughout the entire\npolymerization process. This key information provides a way to rationalize and\ncontrol the coagulation behavior during the whole polymerization process.\n