Mechanical and thermal characterization of polyester composite containing treated wood flour from Palm oil biomass

Abstract

The effect of water and alkali treatment on the thermal decomposition of oil palm shell (OPS) together with the mechanical performance of polyester composites reinforced with treated OPS has been presented in this work. Treatment of OPS with cold/hot distilled water and cold alkali treatment were found to improve the tensile and flexural strength of the resulting composites although the highest mechanical performance was noted with the use of sonication in hot distilled water. On the other hand, hot alkali treatment was found to produce a composite mechanical performance similar to that of the hot distilled water treatment with sonication. FTIR tests indicated that adsorbed water molecules together with some parts of the hemicellulose and lignin were removed by the treatments. Thermogravimetric analysis and scanning electron microscopy of the treated OPS with hot alkali (1%–9% concentration) showed that the mechanical performance reach a peak at 7% alkali concentration with a further increase in concentration resulting in a significant lignin mass loss and decrease in mass residue of the OPS. This trend was attributed to the higher alkali concentration removing hemicellulose as a binder for the cellulose and lignin which resulted in debonding between the filler and matrix components of the OPS and hence a deterioration in fiber structure and resulting poor composite mechanical performance. Therefore, it was concluded that the optimum concentration of alkali treatment required for maximum mechanical performance of natural filler reinforced polymer composites can be obtained simply from thermogravimetric analysis. POLYM. COMPOS., 39:1200–1211, 2018. © 2016 Society of Plastics Engineers

Tribological behavior of unsaturated polyester hybrid composites containing wood flour and carbon nanotubes

“…Such results are in good agreement with findings by other researchers where chemical treatment (alkali, silane and bleaching) of coir fiber was found to reduce the wear rate of polyester composites [19]. It is therefore evident from the results presented above that wood plastic composites with improved mechanical performance [16] can also exhibit superior tribological behavior as a result of enhanced interfacial adhesion between the surface treated filler and polyester matrix. Figure 5d-f shows the influence of MWCNT addition on Ws, µ and Ra for the polyester hybrid composite containing natural filler (palm oil kernel shell).…”

“…These trends can be explained in terms of enhanced interfacial adhesion between the natural filler and matrix through the implementation of the surface treatment for the palm oil kernel powder surface as shown in Fig. 4b and e. In addition, use of an alkali treatment resulted in improved mechanical properties for the WPCs due to the removal of surface impurities which simultaneously cleaned the filler and increased its roughness [16]. Such results are in good agreement with findings by other researchers where chemical treatment (alkali, silane and bleaching) of coir fiber was found to reduce the wear rate of polyester composites [19].…”

“…The soft layer from the wood flour can be due to the presence of lignin part in the lignocellulosic filler. It has been shown in our previous report [16] that a wood flour such as palm oil kernel shell contains 38 wt% cellulose 23 wt% hemicellulose and the rest (39 wt%) can be referred to lignin, wax, and oils molecules. During the wear test, the lignin, wax and oily molecules can act as a lubricant, and cover the surface contact in the worn area which results in less friction.…”

“…In order to study the effect of filler size on the wear properties of WPCs, composites containing 15 wt% of filler were prepared as a function of filler size range (600-300, 300-150, 150-75, 75-50 µm and less than 50 µm) according to a method previously used by the authors [14]. To study the effect of filler treatment, the wood flour was treated by hot alkali treatment under 1, 3, 5, 7 and 9 wt% of alkali concentration with WPC specimens containing 15 wt% of treated wood flour being fabricated as explained by [16]. In addition to these factors, the effect of filler percentage was investigated for WPCs containing 10, 20, 30 and 40 wt% of treated (7 wt% alkali) palm oil kernel shellthis being the optimum surface treatment concentration noted in previous work [15].…”

An investigation into the tribological properties of wood flour reinforced polypropylene composites

“…The mechanical properties of these hybrids can be greatly enhanced by using a compatibilizing agent or surface modification modify interaction among all components. Specifically, the addition of MA-PP can efficiently improve the mechanical and thermal properties of PP/cellulose-fibers composites [25][26][27][28]. It is worthy mentioned that the intercalation of small amounts of coupling agent can significantly promote the mechanical performances these composites [29].…”