Fabrication of Heat Insulation Lining from Oil Palm Trunk Fibre Reinforced Polypropylene Composite

Abstract

Fiber of oil palm trunk from selected tree trunks of a plantation in Nigeria was treated with 5% NaOH aqueous solution to improve its surface characteristics, dried, sorted and used to reinforce polypropylene matrix used to form a composite for insulating thermal flask. Loadings of palm trunk fibre were varied as 10%, 20%, 30% and 40% in polypropylene matrix. Raw and treated oil palm trunk fibre samples were subjected to chemical, mechanical and physical analyses to determine composition, density, hardness, impact and tensile strengths in accordance with ASTM D638 standard using standard equipment. Composite samples were subjected to tests such as hardness, density, impact, tensile strength, thermo-gravimetric and thermal conductivity with equipment that included injection moulding machine, Instron tensile tester, Tinius impact machine, Rockwell hardness tester, Perkin Elmer instrument and Lees disc apparatus accessed at different institutional laboratories. The chemical analysis showed that  the treated fibre had cellulose content of 89.14%; hemicellulose of 6.23%; lignin of 3.51% and ash of 1.02% with no heavy metal oxides that could make it toxic for heat insulation of food carrying containers. TGA and DTG result gave initial and final decompositions at 452ºC and 514ºC respectively which was above the decomposition temperatures of 350⁰C - 435⁰C for conventional domestic insulators. Thermal conductivity of samples declined from 0.0035Wm^-1K^-1 - 0.0015Wm^-1K^-1 for 20 - 40% 10mm thick trunk fibre composite when compared with those of 50mm thick conventional domestic insulators (0.066Wm^-1K^-1 of rock wool; 0.036Wm^-1K^-1of glass fibre and 0.03Wm^-1K^-1of polystyrene)..Palm trunk fibre reinforced composite had less than 10% heat conductivity of conventional domestic insulators and is therefore suitable alternative. .