The present work has been conducted in order to investigate the quality of impregnation of unsaturated polyester resin across the bleached alfa pulpboard, and evaluate the potential for the obtained compound to serve a purpose as a useful composite material.

The ultra-low-angle Microtomy (ULAM) method was used to study the quality of impregnation of alfa fibres by unsaturated polyester resin. The cross-section through the bleached alfa pulpboard/unsaturated polyester material, which emphasised the impregnation zone, was analysed using X-ray photoelectron spectroscopy (XPS). The profiles obtained by the XPS line scan analysis of the tapered surface show a well-defined impregnation region. The depth of this region has been characterised using two chemical constituent peaks, which showed an approximate depth of impregnation of about 20 to 40 μm, on the basis of C-OH/C-O-C, components which are exactly complementary to the β-shifted carbon signal, employed as an analogue for the unsaturated polyester. A comparative study was also carried out between the mechanical and tribological properties of the composite material and the pure unsaturated polyester resin, in order to complement the results obtained by surface analysis. The comparison shows better stiffness, tensile strength at break and wears resistance in the reinforced unsaturated polyester resin.

The results of this research demonstrate a good quality of impregnation of unsaturated polyester resin across the short alfa fibres which present the matrix and reinforcement of the studied composite material.