Combination Of Methyl Methacrylate Bulk Polymerization Kinetics And Heat Transfer Coupling During Thick Organic Glass Production

The organic glass is widely used in the decoration, artworks and airplanes due to its excellent transparent. In the production of the organic glass with grater thickness, the polymerization is easy to be out of control since the reaction heat is greater and the heat transfer is difficult. Due to the lacking of theory instruction, the product is always not fit for the material application required the high transparent and high pressure resistance. From the aspects of heat release and transfer in the bulk polymerization of methyl methacrylate (MMA), the factors affecting the polymerization heat release and heat transfer wereinvestigated in this thesis.The rate and molecular weight models for MMA bulk polymerization are presentedfirstly on the basis of the elementary reactions and species mass balance, and considering the influences cage, gel and glass effects on the rate constants and physical properties. The proposed models are applicable for isothermal and nonisothermal polymerization system and for the polymerization system initiated by individual and composite initiator. The effects of temperatures, type and concentration of composite initiators (AIBN, BPO and DCP) on the kinetics and molecular weight in the polymerization process with temperature change profile were simulated by the models, and compared with the experimental data, with good fitness. The heat release rule is also clear from the model.Heat exchange equation in one dimension is appropriate for MMA bulk polymerizationsystem and is expressed asequation are measured and fit as follows:Physical parameters in thisThe heat release rate â–³Hr_A is provided by the kinetics model aforementioned. Then the temperature, temperature grades and heat flux solutions in organic glass thickness direction during MMA bulk polymerization initiated by AIBN and AIBN/DCP respectively are offered by computer model simulation. It is concluded that the composite initiators with different activities are helpful to prepare the organic glass with stable properties.The coupling of the kinetics model and the heat equation is helpful to understand the process of MMA bulk polymerization and to instruct the production of the organic glass.