Macromolecular Reaction Engineering

The impact of diffusional limitations for three important controlled radical polymerization (CRP) techniques at a laboratory scale and in homogeneous media considering the most important diffusion models and styrene as the monomer are discussed. The formulated insights contribute to a better understanding of CRP processes in the frame of their potential industrial realization.

A literature review of efforts to model the polymerization of styrene under industrial manufacturing conditions is presented. A formal statistical approach is used to select and estimate model parameters and model predictions are compared with literature data obtained using dicumyl peroxide and benzoyl peroxide initiators. Industrial polymerization data are used to validate the model.

Ethylene/1-hexene copolymerization with a novel SiO₂-supported hybrid chromium-based catalyst is investigated. This catalyst is prepared using the residual surface hydroxyl groups in Phillips catalyst to support bis(triphenylsilyl) chromate in order to attain the merits of two important chromium-based catalysts, namely inorganic Phillips and organic S-2 catalysts. The copolymer shows better short chain branch distribution.

Kinetics of methacrylic acid radical polymerization in aqueous solution, with chain transfer by 2-mercaptoethanol, are measured and modeled with the dependence of termination rate on radical chain length, on monomer conversion, and on polymer molar mass being taken into account. PREDICI simulation allows for an adequate representation of measured monomer conversion vs. time profiles.