Cellulose-Containing Fillers for Polymer Composites

The form and sizes of the particles of cellulose-containing disperse systems obtained by dry grinding or dispersing in water a source material (wood pulp and sawdust), destructed by the thermocatalytic method, have been investigated. Their physicochemical and rheological (for aqueous dispersions) properties as well as the physicomechanical properties of composites based on such systems have been studied. By dry grinding, a powder of microcrystalline cellulose (MCC) (in the case of wood pulp) and technical powder (in the case of sawdust) containing particles of sizes from 3 to 20 m were obtained. By dispersing in an aqueous medium the wood pulp destructed to the levelling-off degree of polymerization (LODP), MCC dispersions containing separate microcrystallites and their aggregates were obtained. In the case of their sufficiently high concentration ( 8%), MCC gels having rheological properties typical of liquid-crystalline polymers were formed. It is shown that the cellulose-containing disperse systems obtained may be useful in composites made with polymer materials for improving their strength properties.