Palm olein-based polyol (PP) was used as a partial replacement for commercial sucrose/glycerine initiated polyether polyol (GP) for the production of low density rigid polyurethane foams (RPUFs). The hydroxyl value (OHV) of the GP was 380 mg KOH/g, whereas the OHV for PP was 360 mg KOH/g. The RPUFs were prepared by replacing the GP with PP up to 50 parts per hundred parts of polyols (pph). Characterisation of the RPUFs, including density, compressive strength and strain, cell morphology and thermal conductivity ( k-value), were conducted. The dimensional stability of the foams was also evaluated. The study showed improvement in the compressive strength and strain for palm-based RPUFs with the incorporation of up to 30 pph PP as compared to GP foams. The lowest k-value (0.0232 W/m.K) of RPUF with density below 30 kg/m3 was obtained with the incorporation of 10 pph PP. This was due to the smallest and uniform pore size distribution observed using SEM images. The dimensional stability of the RPUF prepared from PP was within the acceptable range. Thus, the RPUFs made from PP are potential candidates to be used as insulation for refrigerators, freezers and piping.

This study examined the effect of organoclay montmorillonite (OMMT) on the mechanical properties and morphology of flexible polyurethane/OMMT nanocomposite (PU/OMMT) foams prepared from petroleum- and palm olein-based polyols. Palm-based PU foams exhibited inferior mechanical strength as compared to neat petroleum PU foams. However, addition of OMMT significantly improved the foams strength of flexible polyurethane/OMMT nanocomposite foams prepared from palm olein-based polyol (PU bionanocomposite foam). The morphology analysed by scanning electron microscopy (SEM) showed that the cell size of the foam decreased with increasing OMMT content. PU bionanocomposite foam with 5 wt% of OMMT had the most improved tensile (63%) and tear (48%) strengths compared to its neat counterpart. Transmission electron microscopy (TEM) revealed the exfoliated structure of the respective foam. It was concluded that OMMT improved mechanical properties and morphology of PU foams.

No abstract

Glycerol is a major by-product of biodiesel production and finding new uses for glycerol is crucial to ensure the sustainability and continuance of the biodiesel industry. Thus, the transformation of glycerol into ketal compounds that have potential as additive to improve biodiesel properties, could be an option to provide an outlet for increasing glycerol stock. This study aims to optimise the transesterification reaction to afford solketal levulinate ester (SoLE) in highest yield by reacting solketal with methyl levulinate (ML). The reaction parameters varied are type of base catalyst, catalyst concentration, reaction temperature, reaction time and reactants molar ratio. Under optimised reaction conditions: 1.5% sodium carbonate (Na 2 CO 3 ) catalyst loading, reaction temperature of 140°C, reaction time of 4 hr and molar ratio of 3:1 (solketal:ML), as high as 74.5% yield and 95% purity of SoLE was obtained.

The use of Solketal levulinate ester (SoLE) as a potential cold flow improver (CFI) for palm biodiesel is studied. SoLE was added to palm biodiesel and several crucial palm biodiesel characteristics such as density, kinematic viscosity, pour point (PP), cloud point (CP) and cold flow plugging point (CFPP) were evaluated.