Polyurethane composites derived from glycerol and molasses polyols filled with oil palm empty fruit bunches studied by TG and DMA

Polyurethane composites filled with oil palm empty fruit bunches (EFB) were prepared using molasses and glycerol based polyols (MLP and GlyP). Glycerol is a by-product of biodiesel fuel (BDF) from palm oil, and EFB a residual component of the palm oil tree. MLP or GlyP was prepared by dissolving molasses or glycerol in polyethylene glycol. In the first series of composites, the NCO/OH ratio was varied from 0.1 to 0.5 at GlyP/MLP ratio of 50/50. In the second series of composites, the GlyP/MLP ratio was varied from 100/0 to 0/100 at NCO/OH = 0.4. Thermogravimetry (TG), dynamic mechanical analysis (DMA) and static mechanical tests of the above composites were carried out. It was found that thermal properties of the PU composites were markedly affected by the NCO/OH ratio and GlyP/MLP ratio. The thermal stability increased in the presence of molasses component in the polyol mixture. The segmental motion in PU composites was restricted by the presence of glycerol. Static mechanical tests indicated that the degree of cross-linking plays an important role in determining the efficiency of stress transfer from matrix to filler.