Sawdust modification: Maleic anhydride chemical treatment

The aim of this work was to modify the sawdust surface in order to obtain a compatible filler for unsaturated polyesters. Maleic anhydride (MAN) was used as sawdust modifier. The possible esterification of sawdust with MAN was investigated. The efficiency of the treatment was determined by using chemical analysis, infrared spectroscopy (FTIR) and water retention value (WRV) test. Even under mild conditions (room temperature, no catalyst), esterification was achieved. FTIR technique allowed to determine that maleic anhydride reacted by one acid group with the sawdust surface. WRV were analysed using a Langmuir type equation which fitted the experimental results well.