Contribution to the study of glass transition in annealed and tempered silico soda-lime glasses

This research thesis addressed the study of glass transition in some specific glasses. The author first recalls some theoretical approaches and aspects of glass transition in mineral glasses and high organic polymers, as well as some current hypotheses about the structure of silica-based glasses. Then, after a presentation of experimental techniques used during this research, the author shows that the behaviour of annealed glass at temperatures lower than softening, and reports the same kind of study on tempered glass. She makes the distinction between an industrial tempered glass (air cooled after heating of an already solidified glass) and a glass tempered from a molten bath. The study then focuses on glass fibres with the study of the evolution of properties of thin fibres after different thermal treatments at temperatures much lower than the annealing temperature. A theory is then proposed which allows results to be interpreted.