Modification of the properties of pulp fibres for their application in theproduction of composite materials

Modification of sulphite pulp by the treatment with water-soluble silicon-c ontaining compounds, i.e., silica sol and sodium water glass, was carried o ut. The interaction of cellulose with modifiers was studied over a broad ra nge of modifier/pulp mass ratios using chemical analysis, XPS analysis and X-ray spectroscopy. The formation of silicon-containing networks on the sur face of pulp fibres was established. It was shown that the treatment of pul p fibres with both modifiers under investigation influenced their hydrophil ic properties. The formation of silicon-containing networks on the surface of pulp fibres during treatment with silica sol prevented swelling of fibre s, lowered the limiting value of water adsorption and resulted in the narro wing of the hysteresis loop on the adsorption-desorption isothermal of the pulp. The effect of water glass on the hydrophilic properties of pulp depen ds on both its concentration in solution and duration of the treatment. Enhancement of the mechanical strength of single fibres after pulp' treatme nt with both modifiers was observed. Model fibro-cement sheets, by using of modified pulp, were obtained at laboratory and industrial scale. Testing o f the sheets by conventional methods for reinforced fibre-cement sheets exh ibited their applicability as a roof-covering material.