This research is focused to study the effect of wood sawdust (WSD) filled polyurethane (PU) foam with different particle sizes of WSD and different ratio of isocyanate/po1yol [NCO/OH] PU matrix. WSD/PU composite foams were prepared by free-rise casting method using one-shot one-step system. The influence of the particle size on the physical characterization, mechanical behaviour, thermal and morphology
has been studied using WSD with two different particle sizes (45~ and 250 ~). Composite foams were tested for the evaluation of mechanical properties and cell morphologies as a portion of WSD present. For compression strength and modulus, filler loading at 5 php for 45 ~ particle size is the optimum compared to 250 J.IDl particle sizes. However, after exceeding a 5 php value, the properties started to
decrease. The flexural strength and modulus, the trend was similar as observed in compression strength and compression modulus. The hardness of the WSD/PU foam composite decreased with the increasing ofWSD. Scanning electron microscopy (SEM) study showed that regular cell size distribution can be obtained in addition of WSD filler into PU foam composite. The results of thermogravimetric analysis (TGA) showed WSD/PU foam composites has higher thermal stability compared with PU foam. For WSD/PU foam composite with different [NCO/OH] ratio, the compression, flexural and
hardness properties decreased with the decreasing of isocyanate (MDI) content. Scanning electron microscopy (SEM) study indicated that different ratio of WSD in polyuerethane foam Jed to different sizes of closed cell of foam due to lower degree of crosslinking between isocyanate and po1yol. The results of thermogravimetric analysis (TGA) showed that even the ratio of [NCO/OH] is lower, the WSD/PU foam
composites has higher thermal stability compared with PU foam.
