Improvement in the alkali resistance of E-glass fibres using a new 15CaO centre dot 15BaO centre dot 20SiO_2 centre dot 50TiO_2 coating

摘要

E-glass fibres have been coated with a new 15CaO centre dot 15BaO centre dot 20SiO_2 centre dot 50TiO_2 thin film using the sol-gel method. The thermal transformation of the coating is investigated by x-ray diffraction and differential thermal analysis. The changes in the surface of coated and uncoated fibres before and after immersion in 1 M NaOH solution for different times are studied by infrared spectral analysis. Fibre tensile strength has also been measured. The results show that the alkali resistance of E-glass fibres is enhanced by 15CaO centre dot 15BaO centre dot 20SiO_2 centre dot 50TiO_2 coating. Evidence is presented that the alkali corrosion of the coated fibres results in the formation of a Ti rich film that suppresses further corrosion.