DEVELOPMENT AND CHARACTERIZATION OF EHTYLENE-GLYCOL-PLASTICIZED CARBOXYMETHYL CASSAVA STARCH FILMS REINFORCED WITH KAOLIN
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This study focused on the growing environmental concern over conventional petroleum-based plastics by the development and characterization of biodegradable starch-based bioplastic films from carboxymethyl cassava starch. The starch powders were extracted from cassava by cold extraction method which gave a yield percent of 17.3%. The physicochemical properties of the extracted starch resulted in a moisture content 12.3%, pH, 6.0 and gelatinization temperature, 65oC. The cassava starch
was modified to carboxymethyl starch (CMS) for improved mechanical properties. The percentage yield of CMS from the native starch was 59%, degree of substitution and gelatinization temperature gave 0.27% and 50oC. The modified CMS was characterized with Fourier Transform Infrared (FT-IR) Spectroscopy. The FT-IR results showed the presence of O-H, C-H, C-O-C stretching and CO-C ring vibration of carbohydrate, and contained a more intense peaks around 1203-1241cm-1, 1417cm-1 and 932cm-1 which are consistent with the presence of new functional groups which indicates chemical modification of the native cassava starch. The CMS bioplastic films were prepared using casting method by varying ethylene glycol plasticizer (2g, 3g, 4g, 5g) and varying kaolinite filler (0g, 0.5g and 1g) for each weight of the ethylene glycol. The moisture absorption, acid absorption and water absorption showed similar trend of increased absorption as plasticizer levels increases. Films with no filler absorbed more, while filler addition lowered absorption. Solvent solubility showed that bioplastics were soluble in 1M NaOH and showed no significant change (mass and colour) in absolute ethanol. Mechanical testing such as thickness, tensile strength, elongation at break percent and yield percent of prepared bioplastic films were also evaluated. It was discovered that Increasing ethylene glycol improved flexibility but reduces tensile strength, whereas kaolin enhances strength at low plasticizer levels but reduces flexibility. Based on the mechanical testing, the most suitable sample in terms of strength and elongation occurred at 3g plasticizer with 0.5 and 1g filler. Biodegradable ability of prepared bioplastic films were also investigated using the soil burial method and all the films were found to have totally degraded after three weeks. The decomposition nature of prepared biodegradable CMS films was investigated by TGA/DTA. Analysis indicated thermal stability up to 180 – 200oC with kaolin contributing to improve heat resistance. This study demonstrates that CMS based films reinforced with
kaolin and plasticized with ethylene glycol offer an environmental friendly and functional alternative to conventional plastics showing strong potential for sustainable packaging applications.
was modified to carboxymethyl starch (CMS) for improved mechanical properties. The percentage yield of CMS from the native starch was 59%, degree of substitution and gelatinization temperature gave 0.27% and 50oC. The modified CMS was characterized with Fourier Transform Infrared (FT-IR) Spectroscopy. The FT-IR results showed the presence of O-H, C-H, C-O-C stretching and CO-C ring vibration of carbohydrate, and contained a more intense peaks around 1203-1241cm-1, 1417cm-1 and 932cm-1 which are consistent with the presence of new functional groups which indicates chemical modification of the native cassava starch. The CMS bioplastic films were prepared using casting method by varying ethylene glycol plasticizer (2g, 3g, 4g, 5g) and varying kaolinite filler (0g, 0.5g and 1g) for each weight of the ethylene glycol. The moisture absorption, acid absorption and water absorption showed similar trend of increased absorption as plasticizer levels increases. Films with no filler absorbed more, while filler addition lowered absorption. Solvent solubility showed that bioplastics were soluble in 1M NaOH and showed no significant change (mass and colour) in absolute ethanol. Mechanical testing such as thickness, tensile strength, elongation at break percent and yield percent of prepared bioplastic films were also evaluated. It was discovered that Increasing ethylene glycol improved flexibility but reduces tensile strength, whereas kaolin enhances strength at low plasticizer levels but reduces flexibility. Based on the mechanical testing, the most suitable sample in terms of strength and elongation occurred at 3g plasticizer with 0.5 and 1g filler. Biodegradable ability of prepared bioplastic films were also investigated using the soil burial method and all the films were found to have totally degraded after three weeks. The decomposition nature of prepared biodegradable CMS films was investigated by TGA/DTA. Analysis indicated thermal stability up to 180 – 200oC with kaolin contributing to improve heat resistance. This study demonstrates that CMS based films reinforced with
kaolin and plasticized with ethylene glycol offer an environmental friendly and functional alternative to conventional plastics showing strong potential for sustainable packaging applications.
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