Copolymerization of Propylene oxide and Carbon Dioxide at subcritical conditions, with heterogeneous catalysis in batch mode

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System used in Johan Gadolin Process Chemistry Centre at Åbo Akademi University.

As it is well known, CO2 is a Greenhouse Gas (GHG), so it is highly recommended to reduce emissions to the atmosphere for a sustainable future. Capturing CO2 in polymers is a hot research topic nowadays. Concretely, the aim is to develop a polycarbonate from propylene oxide by the Ring Opening Polymerization technique (ROP) introducing CO2 in the recipe (Figure 1).

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Figure 1. Ring Opening Polymerization of Propylene Oxide

There are several successful examples of this reaction, however further development and understanding is needed, in terms of kinetics, mass transfer, phase equilibria and simulation. The reaction takes place at mild conditions using zinc glutarate as catalyst in a discontinuous process. The system consists of three sections: liquid and gas inlets, three-phase reaction and biphasic separation (gas-liquid).

Through techniques like Scanning Electron Microscopy (SEM), X-Ray Powder Diffraction (PXRD), Gel Permeation Chromatography (GPC), Fourier Transform Infrared Spectroscopy (FTIR and FTIR-ATR), the catalyst is defined and molecular weight distribution of the copolymer and the functional groups of the obtained product, respectively, are known.

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Figure 2. Schematic flow diagram of the system.

After the data collection in the experiments, there is enough information to model the copolymerization reaction acquiring the kinetic and mass transfer parameters needed to model the system. A globalized model in the liquid phase and gas phase is used, modelled using MATLAB or Excel-VBA.

 María Pinilla – Johan Gadolin Scholarship

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