Transesterification of sago starch and waste palm cooking oil in densified CO₂

In this work, the synthesis of biodegradable and yet renewable thermoplastics materials through a transesterification reaction of sago starch and waste palm cooking oil (WPO) in densified CO2 as the solvent is reported. The aim of this research is to investigate the potential used of sago starch and WPO as raw materials in the thermoplastics starch synthesis. The starch esters was successfully synthesized using sago starch and WPO as reagent in densified CO2 as shown from the presence of carbonyl group (C=O, 1743 cm-1) in the FT-IR spectra coupled with the presence of the proton (1H-NMR) of the fatty acid in the starch backbone (0.8 - 2 ppm). The product crystallinity decreases as shown in XRD results and resulting with a change in the thermal properties (melting and crystalline temperature) of the products. In addition, the products show a different granular morphology and a higher hydrophobicity compared with native sago starch. This research shows the potential used of sago starch and WPO in the thermoplastics starch synthesis and opens a new perspective on the product application

Pengolahan koleksi di perpustakaan Universitas Mercu Buana Jakarta Barat

ix, 88 hlm.; ilus.; 30 cm

Process-product studies on starch acetylation reactions in pressurised carbon dioxide

An in-depth study on the effect of process conditions (pressure, temperature and type of catalyst) on the acetylation of starch with acetic anhydride in pressurised carbon dioxide is described. A total of 22 experiments were performed and the experimental data were analysed using non-linear multivariable regression. The highest degree of substitution (DS) value (0.46) was obtained using K2CO3 as the catalyst at 90°C, 15 MPa pressure, and a catalyst to starch ratio of 0.5 mol/mol anhydroglucose units (AGUs). Important product properties of the acetylated starch prepared in CO2 like viscosity in water and relevant thermal properties were determined and compared with typical products prepared in an aqueous system.

Supercritical carbon dioxide (scCO2) induced gelatinization of potato starch

The degree of gelatinization (DG) of potato starch after treatment with scCO2 was investigated. A broad range of experimental conditions were applied, including variations in temperature (50-90 °C), pressure (0.1-25 MPa), and the starch water content (16.2-40% wt/wt). Changes in the DG were observed by in situ FT-IR measurements, DSC and confirmed by the XRD analysis. The DG increases at higher temperatures and pressures. A maximum DG of about 14% was achieved at the highest pressure (25 MPa) and temperature in the range (90 °C). A series of experiments under N2 pressure confirms that scCO2 plays a special role in the gelatinization process.

Green starch conversions: Studies on starch acetylation in densified CO2

The acetylation of potato starch with acetic anhydride (AAH) and sodium acetate (NaOAc) as catalyst in densified CO2 was explored in a batch reactor setup. The effects of process variables such as pressure (6-9.8 MPa), temperature (40-90 °C), AAH to starch ratio (2-5 mol/mol AGU), NaOAc to starch ratio (0.1-0.8 mol/mol AGU) and water content (1-15.2%, w/w) on the degree of substitution (DS), the anhydride conversion (XAAH) and the selectivity of the reaction (SSA) were explored. At these conditions, acetylated potato starch with a range of DS values (0.01-0.46) is accessible in densified CO2. The XAAH varied between 10 and 80%, whereas the SSA is relatively low (2-18%). Empirical models were developed to quantify the effects of the process variables on DS, X AAH and SSA. The temperature, water content and NaOAc to starch ratio have the highest effect on the DS, XAAH and S SA values. For comparison, a number of experiments were performed in water and the results confirm that densified CO2 is a good solvent for the starch acetylation reaction. © 2010 Elsevier Ltd. All rights reserved.

Synthesis of fatty acid starch esters in supercritical carbon dioxide

This manuscript describes an exploratory study on the synthesis of fatty acid/potato starch esters using supercritical carbon dioxide (scCO2) as the solvent. The effects of process variables such as pressure (6-25 MPa), temperature (120-150 °C) and various basic catalysts and fatty acid derivatives (methyl- and vinyl esters and anhydrides) on the degree of substitution (DS) were explored in a batch reactor set-up. Products with a broad range of DS values (0.01-0.31) were obtained, the actual values depending on process conditions, type of catalyst and the fatty acid reagent. The combination of K2CO3 and vinyl laurate gave the highest DS values (DS = 0.31 at 150 °C, 8 MPa). The introduction of the fatty acid chains has a profound effect on product properties like hydrophobicity and thermal behavior.