Thermoplasticization of sago residue by esterification with plant oil

Abstract

 In order to establish sago residue as new woody resource for making plastic sheets, the reactivity with plant oil, thermoplasticity, and the solvent suitable for washing the reaction products were evaluated.
 Methanol-water mixture solvent and methanol-hexane mixture solvent were used to extract unreacted products from the esterified sago residue (ESR). In case of methanol-water mixture solvent, the washed ESR showed higher weight increases than samples which were washed with other solvents and it was indicated that the palm oil used as esterification reagent still remained. With methanol-hexane mixture solvent at 8: 2 v/v, the weight of washed ESR was decreased. This indicates that a portion of reaction products must have been dissolved in this solvent. On the other hand, in case of methanol-hexane solvent at 9: 1 v/v, the weight of washed ESR was increased and unreactive palm oil was removed. The methanol-hexane mixture solvent (9: 1 v/v) is, therefore, more suitable than other solvent for washing reaction products. As regards esterification, results of IR spectroscopy and measurement of fatty acids showed that reaction conditions at 140℃ for 4 hours and 160℃ for 2 hours were more suitable than other conditions. Thermoplasticity of plastic sheets made from ESR improved with the addition of glycerol. The plastic sheets from the reaction at 140℃ for 4 hours showed better thermoplasticity than other sheets. The sheets from ESR showed higher modulus of elasticity with glycerol addition.