| Abstrakt: | This thesis presents results of comprehensive kinetics studies of polymerization carried out at various thermodynamic and confinement conditions. The pressure-induced chemical reactions are an appealing synthesis method of large-volume applications, i.e. the production of new materials of well-defined structures and properties of technological interest unobtainable at ambient conditions. The application of pressure allows to simplify the polymerization method, which often requires solvents, initiators and catalysts of complicated structures and complex mechanism of interacting. Also polymerization carried out under spatial confinement conditions is a brand new topic in polymer science, enabling the control of morphology and structure of the recovered polymers on the nanometer scale allowing production of nanofibers, nanorods etc. that can be further utilized in the industry, i.e. in the field of nanotechnology.
The impact of elevated pressure on the reaction kinetics and the properties of recovered polymers was examined and discussed in case of two systems: (i) Ring Opening Polymerization of glycidol and (ii) step growth polymerization of epoxy resin with various amine hardeners. Obtained results clearly revealed that the applied high pressure condition has a significant influence on the polymerization rate, the value of the activation volume (ΔV) and the properties of reaction’s product (like molecular weight distribution or the glass transition temperature). It was observed that the activation volume (ΔV) changes with the thermodynamic condition, affecting the reaction pathways and eliminating the side reactions. Moreover, the reaction rate can be also affected by the application of spatial confinement, which increases together with the applied confinement. However, the values of the activation energy was found to be equaled despite of the pore size used in the preformed experiment.
Obtained results will give new contribution to the scientific knowledge on this issue, mostly due to the lack of similar data available in the literature. Moreover in larger perspective they might be very stimulating achievement and significant step towards better control of the chemical reaction, design of unconventional polymerization methods and novel application of nanomaterials. |