Wettability of glass fibres with different sizings and their adhesion to unsaturated polyester matrices

The wetting characteristics of unsaturated polyester resins on glass fibres with different sizings have been studied by contact angle determination periods. The styrene content of the matrix and the nature of the coatings result to be determinant in the wettability of glass fibres by the polyester matrices. Highest styrene content and styrene-soluble-coatings determine better wetting characteristics. Mechanical properties of the cured specimens and scanning electron microscopy on the fracture surfaces were also performed. Interesting correlations between the nature of the sizing agent and cohesive energy density with mechanical properties and fibre/matrix adhesion were found.[/p]