Control of Molecular Weight Distribution in Emulsion Polymerization Using On-Line Reaction Calorimetry

• Published in: Industrial & engineering chemistry research Vol. 40; no. 1; pp. 218 - 227
• Main Authors: Vicente, Matias, BenAmor, Selwa, Gugliotta, Luis M, Leiza, Jose R, Asua, Jose M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10.01.2001
• Subjects: Applied sciences; Exact sciences and technology; Industrial polymers. Preparations; Polymer industry, paints, wood; Technology of polymers; Thermoplastics; Free radical polymerization; Molecular weight distribution; Emulsion polymerization; Process control; Open loop; Theoretical study; Calorimetry; Styrene polymer; Kinetics; Latex
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie000387e

The molecular weight distribution (MWD) of linear polymers was controlled based on on-line reaction calorimetry. A method to estimate the MWD from reaction calorimetry when chain transfer to a chain-transfer agent is the main termination event was developed and its robustness assessed by simulation. Following this method, the desired final MWD was decomposed in a series of instantaneous MWDs to be produced at different stages of the process. An optimization algorithm was used to calculate the set-point trajectories to produce the desired MWD in a minimum time. A nonlinear model based controller was used to track these trajectories. The control scheme was validated by preparing polystyrene latexes of widely different predefined MWD.