Influence of compatibilizers on the surface hardness, water uptake and the mechanical properties of poly(propylene) wood flour composites prepared by reactive extrusion

• Published in: Macromolecular materials and engineering Vol. 276-277; no. 1; pp. 51 - 58
• Main Authors: Nitz, Hansjörg, Reichert, Peter, Römling, Hartmut, Mülhaupt, Rolf
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.03.2000; WILEY‐VCH Verlag GmbH
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/(SICI)1439-2054(20000301)276:1<51::AID-MAME51>3.0.CO;2-Z

Anisotropic wood flour (WF) particles, composed of fiber bundles, were melt compounded in a twin screw extruder at 200°C together with poly(propylene) (PP) in the presence of maleic anhydride‐grafted poly(propylene) (PP‐g‐MA) and maleic anhydride‐grafted poly‐(styrene)‐block‐poly(ethene‐co‐1‐butene)‐block‐poly(styrene) (SEBS‐g‐MA). Mechanical properties, surface hardness, and water uptake were monitored as a function of compound composition and type of compatibilizer. PP/WF/SEBS‐g‐MA containing 30 vol.‐% (40 wt.‐%) WF and 3.5 vol.‐% (3 wt.‐%) SEBS‐g‐MA gave Shore hardness of 78 with respect to 70 for PP and increased simultaneously Young's modulus (100%), yield stress (20%) and notched Izod impact strength (24%). SEBS‐g‐MA compatibilizer addition did not affect the surface hardness but accounted for substantially reduced water uptake and excellent interfacial adhesion. In comparison to talcum‐filled PP, PP/WF/SEBS‐g‐MA composites exhibited lower density combined with higher specific strength, specific Young's modulus, and higher surface hardness. WF particle as well as composite morphologies were imaged by means of enviromental scanning electron microscopy (ESEM).