A series of chemically modified starches has been synthesized in the present study. The hydroxyl groups in starch molecules were substituted by ionic groups (acetate sodium or trimethylammonium chloride) and hydrophobic groups (hexanoyl group or benzoyl group). The FTIR spectra showed that the hydrogen bonds present in natural starch were weakened by the chemical modification. […]
Biodegradable material can be defined as a material that has a proven capability to decompose in a specific environment within a period through natural biological processes into non-toxic carbonaceous soil, water, carbon dioxide, or methane. Apparently, natural starch is a biodegradable material. In this dissertation, natural starch has been chemically modified by various functional groups, […]
Thermal Stability of Chemically Modified Starch The thermal stability of chemically modified starch was characterized by thermogravimetric analysis (TGA) in a nitrogen atmosphere. Figure 4.5 shows how the thermal degradation temperature of a starch was changed by chemical modification. The thermal degradation temperature is defined by the temperature at which the weight loss of a […]
In our exploration of modified starches, Figure 4.4 emerges as a key player, showcasing the intricate dance between these starch variants and moisture over time in a consistent 75% humidity environment. The revelations are profound, shedding light on the hydrophilic and hydrophobic tendencies that define the behavior of starch in various forms. Hydrophilic Symphony: Natural […]
As described in Introduction to natural starch, there are three hydroxyl groups in each repeat unit of starch molecules. Chemical modification explored in the present study is to substitute these hydroxyl groups with functional groups, such as anionic groups, cationic groups, hexanoyl groups, or benzoyl groups. The rationale behind this modification was as follows. Figures […]
Proton Nuclear Magnetic Resonance (1 H-NMR) Spectroscopy 1 HNMR spectra were obtained with a Varian Gemini 300 MHz NMR spectrometer. Solid samples were solubilised in deuterated dimethyl sulfoxide (DMSO-d6) and placed in 5 mm NMR tube. The spectra were collected at 25 oC over a spectra width of 4796 Hz using a 90o pulse. The […]
Solution Blending of Blends of Modified Starch and EVOH A predetermined amount of modified starch and EVOH were dissolved into dimethyl sulfoxide(DMSO) at a mildly elevated temperature (around 60 oC). A magnetic stirrer was used to facilitate the dissolution. A transparent and yellowish solution was obtained after total dissolution of polymers. The solution was put […]
Starch employed in this study is a cornstarch purchased from Sigma-Aldrich Chemical Company. Other chemicals used for the synthesis were purchased from SigmaAldrich Chemical Company, and they were used as received without further purification. Natural clay (montmorillonite, MMT) and two commercial organoclays (Cloisite 30B and Cloisite 15A) used in the preparation of nanocomposites were provided […]
Starch, a crucial carbohydrate, serves as a primary source of biological energy for animals. Derived from various plants such as potato, corn, wheat, and rice, it undergoes hydrolysis through specific enzymes during animal metabolism. This article delves into the intricate compositions and structures of natural starch, shedding light on its significance in the realm of […]