http://univ-bejaia.dz/dspace/123456789/2205 Tue, 07 Apr 2026 10:47:27 GMT 2026-04-07T10:47:27Z http://localhost:80/jspui/retrieve/3967/ http://univ-bejaia.dz/dspace/123456789/2205 http://univ-bejaia.dz/dspace/123456789/25221 Title: Evaluation of natural biodegradation of low-density polyethylene/modified corn flour composites Authors: Sahi, Samira; DJIDJELLI, Hocine; BOUKERROU, Amar Abstract: Composites based of low density polyethylene (LDPE) reinforced with acetylated corn flour (ACF) at proportion of 10, 30 and 50 (%.Wt) were prepared. The biodegradation of resulting composites was studied in the environment using the soil burial test. The biodegradation were evaluated by different analysis techniques and were compared with the results recorded on these composites before the biodegradation test. Differential scanning calorimetry (DSC) analysis showed an increase of the melting enthalpy and crystallinity of LDPE with evidence of degradation. The biodegradability of the composites was enhanced with increasing ACF content in the matrix. This result was supported by decrease in mechanical properties, by weight loss and degraded surface of composites observed through morphological studies. Sat, 29 Jul 2023 00:00:00 GMT http://univ-bejaia.dz/dspace/123456789/25221 2023-07-29T00:00:00Z http://univ-bejaia.dz/dspace/123456789/25219 Title: Study of the biodegradation of composite materials reinforced with natural resources recovered from industrial areas Authors: BELLILI, Nadira; DAIRI, Badrina; GUIZ, Nour Elhouda; DJIDJELLI, Hocine; BOUKERROU, Amar Abstract: The aim of our work is to contribute to the search for solutions to the problem linked to environmental pollution by plastic materials and lignocellulosic waste. Composites based on polyvinyl chloride/olive pomace flour (PVC/FGO) with 20% fiber content were prepared. The lack of compatibility between plant fibers and some polymers is due to the hydrophilic nature of plant fibers and the more hydrophobic nature of the matrix. This incompatibility causes poor dispersion of the fibers and the formation of a heterogeneous material whose overall mechanical properties are not satisfactory. In order to improve adhesion at the fiber/matrix interface, the fibers were modified by gamma irradiation. To complete this work, it is essential to carry out an in-depth study of the biodegradation of the materials produced. The PVC/FGO composites were subjected underground under environmental conditions. The changes induced by the exposure of composite materials to biodegradation were evaluated by optical microscopy and the measurement of mass loss. Sat, 29 Jul 2023 00:00:00 GMT http://univ-bejaia.dz/dspace/123456789/25219 2023-07-29T00:00:00Z http://univ-bejaia.dz/dspace/123456789/25218 Title: Biodegradation in compost environment of PLA bioplastic containing brown algae biomass Authors: IHAMOUCHEN, Chadia; AOUDIA;, Nadia; DJIDJELLI, Hocine; BOUKERROU, Amar Abstract: This work was focused to the study of the biodegradation of poly lactic acid (PLA) alga composites in compost environment over a period of 50 days. To highlight the interaction between the natural reinforcement and the matrix, an in-situ grafting of maleic anhydride directly during the implementation in the extruder, will be consider to act as a compatibilizing agent (PLA-g-MAH) in the PLA/Algae system. The monitoring of the degradation process was evaluated by infrared structural analysis, mass loss and mechanical tensile analysis. The results revealed that the mass change is positive, suggesting that the chain scission phenomenon predominates over the cross-linking phenomenon. The mass loss increases with the loading rate, processing and composting time. The tensile test study revealed a decrease in stress and elongation and an increase in stiffness with the addition of the untreated filler. The treatment resulted in an improvement in mechanical properties. After 50 days in the compost medium, it was found that all the parameters underwent a clear decrease due to the chain scission reactions by enzymatic hydrolysis. For the FTIR results, an increase in the intensity of the O-H absorption band at 3325 cm-1 was observed with the untreated load, due to its high OH concentration. With treatment, this decreases, attributed mainly to the decrease in the hydrophilic character of the feed after treatment. After 50 days of composting, we have a decrease of the absorption band located at 1120 cm-1 (υ C-O) which corresponds to the hydrolysis of the ester bond. The appearance at 1620 cm-1 of a new band corresponds to the ends of carboxylic acid chains (COO) generated by enzymatic hydrolysis, due to microorganisms that consume lactic acid and surface oligomers Sat, 29 Jul 2023 00:00:00 GMT http://univ-bejaia.dz/dspace/123456789/25218 2023-07-29T00:00:00Z http://univ-bejaia.dz/dspace/123456789/25217 Title: Study of PHBV/PP mixtures: Preparation and physicochemical characterization Authors: HAMOUR, Noura; BELLILI, Nadira; DAIRI, Badrina; BOUKERROU, Amar; BEAUGRAND, Johnny Abstract: This research work consists in studying the structure-properties relationships of biopolymer mixtures based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polypropylene (PP) elaborated by casting process according to the composition in terms of morphology, structure and thermal properties. The results showed a synergistic effect of glycerol addition on the thermal and morphological properties of the PHBV/PP blends. Sat, 29 Jul 2023 00:00:00 GMT http://univ-bejaia.dz/dspace/123456789/25217 2023-07-29T00:00:00Z