Solid wood from various chemical wood modification processes (commercial: thermo treatment, acetylation, furfurylation, laboratory scale: various cross-linking reactions) was milled in hammer- and knife-mills to produce particles for the use in Wood Polymer Composites (WPC). The composites of modified wood were compared to those of untreated particles of the same species; this was of importance, because different wood species were used particularly in the commercial processes. The wood particles were evaluated regarding size and geometry via mesh analysis and microscopy. The particles were compounded with polypropylene as thermoplastic matrix polymer in an extrusion process and than molded into test specimens via compression moulding. The mechanical properties were tested with regard to tensile strength, bending strength and impact bending strength. Water uptake was assessed in cold and boiling water test. The use of modified wood particles resulted in an increase in dimensional stability of WPC test specimen. Water uptake was partly reduced up to 60%. The mechanical properties were significantly increased for some modified particles in dependence of the treatment and without coupling agents.
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