Development of biodegradable plastic composite blends based on sago derived starch and natural rubber

Polyethylene is a widely used packaging material, but its non-biodegradable nature can lead to waste disposal problems. This increases the concern in research and development of biodegradable plastics from natural resource as alternatives to petroleum-derived plastics. In this study, biodegradable plastic composites were prepared by blending thermoplastic starch with natural rubber in the present of glycerol as plasticizer. Local sago starch was cast with 0.5 to 10% of natural rubber to prepare the bioplastic. The products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), water absorption test, biodegradable test, hydrolysis test, and mechanical analysis. Meanwhile, composite with natural rubber latex was increased from 0.5 to 10% showing that the melting temperature is in the range of 120 to 150 °C, but with no significant difference. The water absorption characteristics, biodegradability, and tensile strength decreased by 11.21%, 30.18%, and 20.733 MPa, respectively. However, the elongation at break was increased from 26.67 to 503.3%. The findings of this study showed that sago starch has a great potential in bioplastic production with good miscibility and compatibility

Development of biodegradable plastic from sago and Bario rice starch blend.

Biodegradable plastic composites were prepared by casting thermoplastic starches (Bario rice/Sago starch at ratio 2:3) with natural rubber (0.5 - 10 %) in the presence of a plasticizer. Bioplastics produced were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), water absorption test, biodegradable test, and mechanical analysis. Increasing natural rubber latex content in the composites showed shifting of melting temperature with increment by 8 - 23 degrees C, decreased water absorption ability by 18.2 %, decreased biodegradability by 15.0 to 36.8 % and reduced tensile strength by 1.8 to 7.6 %. These properties suggested that Bario rice has good potential in bioplastics casting

Characterization of bioploymers produced from different blends of chemically modified starch and natural rubber latex

Development of biodegradable polymers from absolute environmental friendly materials has attracted increasing research interest due to public awareness of waste disposal problems with low degradable conventional plastic. In this study, starch and natural rubber latex which abundant, were assessed for their potential in making biodegradable polymers. Sago starch and rice starch with low and high amylose contents were chosen and chemically modified via acetylation and hydroxypropylation. Starches with and without chemical treatments were gelatinized and later casted with natural rubber latex in the following ratios 100.00/0.00, 99.75/1.25, 98.50/2.50, 95.00/5.00, 90.00/10.00 and 80.00/20.00 wt/wt, for preparing biopolymer films using solution spreading technique. The products were evaluated according to their water absorption, mechanical, thermal, morphological and biodegradable properties. Level of substitution showed that starches were successfully chemical modified. Acetylation of sago, LAR and HAR gave result of DS 1.05, 1.35 and 1.30 respectively. Hydroxypropylation of sago, LAR and HAR gave result of MS 0.13, 0.27 and 0.31 respectively. FTIR (Fourier Transform Infrared) analysis proved that acetyl and hydroxypropyl groups were successfully substituted into the starch macrostructures after the chemical substitutions. These substitutions improved starch water solubility and their compatibility with natural rubber latex in the film fabricating process via solution casting. Modifications of starches by either acetylation or hydroxypropylation increase water absorption ability of product films about 2 to 5 times higher compare to native starch product films. In terms of compatibility with natural rubber latex, high amylose rice, native and acetylated sago starch proved to be compatible and had good adhesion with natural rubber latex through SEM result. However, both modification modes did not exhibit differences trend in their thermal profile. Sago starch and rice starch product films showed similar trend of thermal and mechanical properties. Product films formulated from sago starch absorbed less water as compared to rice starch. Native sago starch product film showed 110% in water absorption capacity. However, native LAR and HAR product films showed 190 and 300% in water absorption capacity. Water absorption capacity of all type of biopolymer was able to reduce up to 95% when addition of natural rubber latex concentration reached 20%. Addition of natural rubber latex delayed biodegradable threshold of product films, but they were still completely biodegradable in the natural environment. Product films with less than 2.5% natural rubber content was totally biodegraded within 2 to 6 weeks. However, as concentration of natural rubber latex increase to 20%, biodegradability of the film still achieved 50% within 12 weeks. Product films with high natural rubber latex content exhibit high melting temperatures, inhibited the absorption of water and increased elongation at break. From the analysis of product films, it can be concluded that the ratio of the starch to natural rubber latex, selection of chemical substitution modes and types of starch played an important role in determining characteristics of final product blends. Biopolymer films with desirable properties can be fabricated by choosing an appropriate casting formulation

Characterization of bioploymers produced from different blends of chemically modified starch and natural rubber latex.

Development of biodegradable polymers from absolute environmental friendly materials has attracted increasing research interest due to public awareness of waste disposal problems with low degradable conventional plastic. In this study, starch and natural rubber latex which abundant, were assessed for their potential in making biodegradable polymers. Sago starch and rice starch with low and high amylose contents were chosen and chemically modified via acetylation and hydroxypropylation. Starches with and without chemical treatments were gelatinized and later casted with natural rubber latex in the following ratios 100.00/0.00, 99.75/1.25, 98.50/2.50, 95.00/5.00, 90.00/10.00 and 80.00/20.00 wt/wt, for preparing biopolymer films using solution spreading technique. The products were evaluated according to their water absorption, mechanical, thermal, morphological and biodegradable properties. Level of substitution showed that starches were successfully chemical modified. Acetylation of sago, LAR and HAR gave result of DS 1.05, 1.35 and 1.30 respectively. Hydroxypropylation of sago, LAR and HAR gave result of MS 0.13, 0.27 and 0.31 respectively. FTIR (Fourier Transform Infrared) analysis proved that acetyl and hydroxypropyl groups were successfully substituted into the starch macrostructures after the chemical substitutions. These substitutions improved starch water solubility and their compatibility with natural rubber latex in the film fabricating process via solution casting. Modifications of starches by either acetylation or hydroxypropylation increase water absorption ability of product films about 2 to 5 times higher compare to native starch product films. In terms of compatibility with natural rubber latex, high amylose rice, native and acetylated sago starch proved to be compatible and had good adhesion with natural rubber latex through SEM result. However, both modification modes did not exhibit differences trend in their thermal profile. Sago starch and rice starch product films showed similar trend of thermal and mechanical properties. Product films formulated from sago starch absorbed less water as compared to rice starch. Native sago starch product film showed 110% in water absorption capacity. However, native LAR and HAR product films showed 190 and 300% in water absorption capacity. Water absorption capacity of all type of biopolymer was able to reduce up to 95% when addition of natural rubber latex concentration reached 20%. Addition of natural rubber latex delayed biodegradable threshold of product films, but they were still completely biodegradable in the natural environment. Product films with less than 2.5% natural rubber content was totally biodegraded within 2 to 6 weeks. However, as concentration of natural rubber latex increase to 20%, biodegradability of the film still achieved 50% within 12 weeks. Product films with high natural rubber latex content exhibit high melting temperatures, inhibited the absorption of water and increased elongation at break. From the analysis of product films, it can be concluded that the ratio of the starch to natural rubber latex, selection of chemical substitution modes and types of starch played an important role in determining characteristics of final product blends. Biopolymer films with desirable properties can be fabricated by choosing an appropriate casting formulation

Effect of germination on γ-oryzanol content of selected Sarawak rice cultivars

Problem statement: Rice is rich in complex carbohydrates and beneficial bioactive compounds such as γ-Aminobutyric Acid (GABA), γ-oryzanol and vitamin. Several bioactive components are known to accumulate in rice during germination process. This study was to investigate the effect of germination process on γ-oryzanol levels in selected Sarawak local rice cultivars. Approach: Rice seeds were germinated for 4, 8, 12, 16, 18, 20 or 24 h at 25°C and samples were processed and analyzed for γ-oryzanol content. A partial extraction method was used for quantitative γ- oryzanol analysis. Results: Result showed γ-oryzanol concentrations in the rice cultivars varied from 0.099-0.340 mg g-1 on dry weight basis. Cultivars Udang Halus and Silah showed the highest concentration of γ-oryzanol after 16 h germination. Conclusion: The germination process exhibited diverse effects on the γ-oryzanol accumulation in rice and it was cultivar dependent

Development of biodegradable plastic composite blends based on sago derived starch and natural rubber

Polyethylene is a widely used packaging material, but its non-biodegradable nature lead to waste disposal problems. This has caused concerns and increased efforts on research and development of biodegradable plastics from natural resources as alternatives to the petroleum-derived plastics. In this study, biodegradable plastic composites were prepared by blending thermoplastic starch with natural rubber in the presence of glycerol as plasticizer. Local sago starch was casted with 0.5 to 10% of natural rubber to prepare the bioplastic. The products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), water absorption test, biodegradability test, hydrolysis test and mechanical analysis. Composites with increasing natural rubber latex component from 0.5 to 10% showed melting temperature in the range of 120 to 150 °C. The water absorption characteristic, biodegradability and tensile strength decreased by 11.21%, 30.18% and 20.733 MPa respectively. However, the elongation at break was increased from 26.67 to 503.3%. This study showed that sago starch has good potential in bioplastic production with good miscibility and compatibility