STUDY ON BIODEGRADABLE AND ANTIMICROBIAL PROPERTIES OF BIOWASTE CHITIN-POLYVINYL ALCOHOL BLENDED FILM

The film forming ability of chitin (CT) blended with polyvinyl alcohol (PVA) were prepared with a seriesof nine different ratios of CT:PVA, (10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10v/v),using 2% chitin solution and 10% polyvinyl alcohol solution. All prepared blended films have a highlytransparent, smooth surface and pale-yellow color. The prepared blended films were characterized by usingthe physical parameters, the physico-mechanical properties, the degree of swelling, and water uptake. Asmeasured by the swelling and water uptake, the blended films showed a higher degree of hydration, as aresult of varying the weight percent of PVA in the membrane matrix. Comparative characterization of theprepared blended films included FT IR and TG-DTA analysis. From the FT IR analysis, the characteristicabsorption peaks of CT-PVA blended film clearly showed that the two polymers were well mixed.According to TG-DTA analysis, the thermal stability of the CT-PVA blended film was found to be slightlylower. The various types of CT-PVA blended films were also tested for antimicrobial activity using anagar disc diffusion method. From these results, all of the prepared CT-PVA blended film showedpronounce antimicrobial activities. Subsequently, the biodegradable nature of the prepared CT-PVAblended films was studied through the soil burial test. Finally, the prepared CT-PVA blended films can beused in wound dressing, and also as packaging materials.

ISOLATION OF CELLULOSE DERIVED FROM ORANGE PEEL AND ITS APPLICATION IN BIODEGRADABLE FILMS

"In this study, cellulose was extracted and isolated from orange peel (OP) via alkaline treatment, followed by a bleaching process. The orange peel derived cellulose (OPDC) was characterized and compared with microcrystalline cellulose (MCC). FTIR characterization confirmed the absorption peaks of cellulose for both OPDC and MCC. From the DSC analysis, it was found that MCC possessed higher thermal stability than OPDC. In addition, the results of FESEM and particle size analysis revealed the micro-size dimension of OPDC after the pretreatments. The crystallinity index (CrI) of OPDC (80.14%) was found to be significantly higher than that of untreated OP (23.54%). After that, biodegradable blended films with different weight ratio were prepared using OPDC and MCC with polyvinyl alcohol (PVA) by the solution casting method. According to the FTIR spectra, the shift of the characteristic absorption band and the change of the band intensity observed in the spectra of the PVA/OPDC blended films were similar to those of the PVA/MCC blended films. This confirmed the development of new inter- and intramolecular hydrogen bonds and changes in the conformation between PVA and cellulose. The tensile strength and elongation at break of both PVA/OPDC and PVA/MCC blended films decreased when the cellulose content increased in the PVA matrix. However, the elastic modulus of both films was enhanced when the amount of cellulose increased. By comparison, the PVA/OPDC blended film presented higher tensile strength and elastic modulus than the PVA/MCC blended film. Based on the natural weathering tests, the degradability of blended films increased with a rising amount of cellulose after exposure to degradation tests. The biodegradability of blended films was confirmed by the tiny black spots observed on their surface, which reflected the growth of microorganisms. It was further proven by the morphology studies performed on the surface of the films using FESEM."

Potentiodynamic Polarization Performance of a Novel Composite Coating System of Al2O3/Chitosan-Sodium Alginate, Applied on an Aluminum AA6063 Alloy for Protection in a Chloride Ions Environment

In this research work, a preliminary potentiodynamic polarization performance testing was carried out on a new environmentally friendly proposed composite coating. The proposed composite coating was developed by: (a) hot sulfuric anodizing to produce an Al2O3 conversion film followed by an (b) organic electrodeposited chitosan–sodium alginate blended film. Posteriorly, the conversion and organic films were microstructurally characterized by scanning electron microscopy. Finally, the polarization resistance technique was used to measure the corrosion resistance of the uncoated and coated AA6063 alloy in a simulated marine environment and the polarization tests were compared to samples immersed during 30 days in same electrolyte solution. The obtained inhibition corrosion efficiency of the proposed coating system was measured comparing the Rp of the uncoated alloy to the coated samples, showing an efficiency about 99% for a 3% NaCl electrolyte for some of the samples. Therefore, the experimental results obtained during this research demonstrates the feasibility of using the developed anticorrosive composite coating to protect aluminum alloys against chloride corrosive ions species and to further continue with the corresponding research.

Antioxidant, Mechanical and Physical Properties of Chicken Skin Gelatin/CMC Film Incorporated with Centella asiatica Extract

This study aimed to characterize the antioxidant, mechanical and physical properties of chicken skin gelatin/CMC/Centella asiatica blended film. The influence of Centella asiatica at 0.3% and 0.7% on antioxidant activities; mechanical properties and physical properties of chicken skin gelatin/CMC/Centella asiatica film were investigated. Characterization of the blended films with 0.7% Centella asiatica extract shows higher antioxidant activities with a total phenolic content of 0.36 mg/g of GAE, DPPH of 89.26%, and reducing power of 0.80 nm compared to 0.3% Centella asiatica extract. The addition of 0.3% of Centella extract provide higher value in tensile strength (5.0 × 10−2 MPa), elongation at break (281%), melting point (131.31 °C), transparency (0.86) but lower UV-light penetration. While the addition of 0.7% Centella extract contribute to higher value in WVP (1.13 × 10−4 g m−1s−1Pa−1) and puncture test (0.06 N). There are no significant differences between functional groups obtained from this blended film as evaluated by FTIR analysis (p > 0.05). Furthermore, XRD analysis showed the addition of extract decrease the crystallinity of film. In conclusion, the incorporation of Centella asiatica extracts on film greatly increased antioxidant levels and improved some of the mechanical and physical properties of the film blends.