Browsing by Author "Irinislimane, Ratiba"

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Application of Fourier Transform Infrared (FT-IR) Spectroscopy to the Study of the Modification of Epoxidized Sunflower Oil by Acrylation
(Sage journals, 2012) Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
Commercial sunflower oil was epoxidized at the laboratory-scale. The epoxidized sunflower oil (ESFO) was modified following the acrylation reaction. Modification was carried out simultaneously using acrylic acid (AA) and triethylamine (TEA). To optimize the reaction conditions, the effects of four temperatures (40, 60, 80, and 100 °C), the ESFO:AA (100:100) ratio, and 0.2% TEA were investigated. The rate of conversion was analyzed with both FT-IR and titration of the oxirane ring. After that, the temperature with the highest conversion was selected and used throughout for all modification reactions. Then, four ratios (100:100, 100:90, 100:80, and 100:75) of ESFO:AA were analyzed at four different concentrations of TEA (0.2, 0.3, 0.4, and 0.5%) to determine the best estimate for both the ESFO:AA ratio and the catalyst concentration. Conversion rate was analyzed using FT-IR spectroscopy by measuring the concentrations of ester, carbonyl, and alcohol groups. Moreover, oxirane***ring concentration was estimated using the titration method (with gentian violet as indicator) and FT-IR spectroscopy (epoxy ring absorptions at 1270 cm−1 and 877 cm−1). Based on conversion yield, the optimum ESFO:AA ratio corresponds to 100:80; the best temperature reaction was at 60 °C, and the best TEA concentration was 0.2%. The critical amounts of reactants needed to reach maximum conversion were established. The final acid value of the acrylated ESFO after washing (pH = 7) was 2.1 mg potassium hydroxide (KOH) g−1. All results show that FT-IR spectroscopy is a simple, low-cost, rapid method for investigating the kinetics of a reaction
Elaboration and Characterization of Polyurethane Foams Based on Renewably Sourced Polyols
(Spriger link, 2020) Kahlerras, Zineb; Irinislimane, Ratiba; Bruzaud, Stephane; Belhaneche-Bensemra, Naima
The aim of this work is to prepare and characterize a series of bio-polyurethane foams (Bio-PUFs) based on renewably sourced polyols in order to increase their ecological potential, while maintaining their properties. Polyurethane foams (PUFs) were obtained using two sunflower based-polyols (SF-P1 and SF-P2) with different hydroxyl numbers synthesized through the acid-catalyzed ring-opening of epoxidized sunflower oil (ESFO) and subsequent partial reduction of the ethylenic linkages to give hydroxyl moieties. These SF-Ps were applied for replacement of petrochemical polyol Confort P0010 with a mass fraction of SF-P in the range of 40–100%. The resins were characterized by Fourier transform infrared (FTIR) spectroscopy. Their solution viscosity and thermal behavior were investigated. The obtained SF-Ps were reacted with diisocianates to yield PUFs at a fixed NCO index. Several experiments were conducted by varying the amounts of polyols, isocyanate, catalysts, and surfactants until acceptable foams were obtained. The structures of the obtained PUFs were confirmed by FTIR spectroscopy and scanning electron microscopy (SEM). The morphology, the apparent density, the thermal behavior (thermogravimetric analysis and differential scanning calorimetry), and the thermal conductivity of the PUFs were investigated. The study showed that it is possible to substitute petrochemical polyols by the addition of SF-P to achieve PUFs with desirable properties. It was found that the mixing of SF-Ps in formulations influences especially the thermal and morphological properties, and increases the end product renewable material content. The highest renewable material content showed SF-PUFs (reaching 76%) since the renewable material content in SF-P is high (~ 92%). As a result of the SF-Ps loading in the range of 40–100% the PUFs change from flexible to semi-flexible structures. Furthermore, they become denser and exhibit numerous cell shapes, such as semi-open cells and closed cells
Novel biocomposites based on sunflower oil and alfa fibers as renewable resources
(Springer, 2018) Kadem, Sihem; Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
Novel biocomposites based on sunflower oil and alfa fibers as renewable resources
(Springer, 2018) Kadem, Sihem; Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
Optimisation of operatory conditions for synthesis of sunflower Oil biobased polyols using design of experiments and spectroscopic methods
(Springer, 2021) Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
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Properties Investigation of Epoxidized Sunflower Oil as Bioplasticizer for Poly (Lactic Acid)
(Springer, 2021) Bouti, Mohamed; Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
This study aims to improve low intrinsic ductility of poly (lactic acid) (PLA) by using a novel bio-sourced plasticizer environmentally friendly and cost-effective and to get a fully biodegradable material with potential application in films manufacturing. For that purpose, commercial sunflower oil (SO) was epoxidized and epoxidized sunflower oil (ESO) was used as plasticizer for PLA. To investigate ESO potential as plasticizer for PLA, its plasticizing effect was compared with commercial epoxidized soya bean oil (ESBO). Bioblends based on PLA and epoxidized vegetable oils (EVO) as bioplasticizers were prepared. The plasticizers (ESO or ESBO) were respectively compounded with PLA at 10, 20, 30, and 40 wt%. Mechanical (tensile and Shore D hardness), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) and morphological properties (optical microscopy and scanning electron microscopy (SEM)) were characterized. The results showed that the addition of ESO or ESBO to PLA decreased tensile strength and tensile modulus compared to neat PLA but increased elongation at break for which an optimum (9 %, 16 and 34 % for ESBO, ESO5.5 % and ESO6.5 % respectively) was reached at a content of 20 wt% of plasticizer. The structures of the obtained plasticized PLA were confirmed by FTIR spectroscopy. The thermal properties (DSC), such as glass transition temperature (Tg) and melting temperature (Tm) were slightly decreased by addition of plasticizer into PLA, indicating that plasticizer increases the chain mobility and SEM analysis proved successful modification on the PLA brittle morphology with addition of EVO. On the other hand, TGA results revealed increase in the thermal stability. Also the results showed the effect of the EVO weight and the epoxy content (O.O value) on the improvement of the properties of PLA. ESO6.5 % at 20wt% was an efficient plasticizer for PLA
Study of the interfacial adhesion between alfa fiber and synthetic resin in a new biocomposite material
(Elsevier, 2022) Kadem, Sihem; Irinislimane, Ratiba; Belhaneche-Bensemra, Naima
The Interfacial adhesion between fiber and resin has a strong influence on composite mechanical performance and thermal stability. Natural fibers like alfa have attracted a great interest to be used as reinforcement for polymer composites. In this work biocomposites were prepared from natural substances by bleinding alfa plants (Stipa tenacissima) as natural reinforce fibers and modified sunflower oil (Helianthus annuus) as synthetic resin. The application of alfa fibers as reinforcement for composites requires a strong adhesion between the fibre and the resin. In the present work, alfa fibers were added to the synthetic resin after alkaline treatment with 5% NaOH solution. Biocomposites were prepared by using treated and untreated alfa fibers and characterised in terms of tensile properties, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed a good interfacial adhesion between treated alfa fibers and the resin. On the other hand, a thermal improvement was observed for biocomposites with treated alfa fibers
Valorization of regenerated LDPE by blending with EPDM in the presence of peroxide
(2007) Irinislimane, Ratiba; Belhaneche-Bensemra, Naima; Benlefki, A.
The present work aims to the valorization of regenerated low density polyethylene (LDPE) by blending with small quantities of ethylene-propylene-diene monomer (EPDM). Three types of regenerated LDPE (rLDPE) from different waste sources (greenhouses, milk pouches,...) were characterized in terms of physico-chemical (density, melt flow index, water absorption, melting temperature and structure by Fourier transform infrared (FTIR) spectroscopy) and mechanical properties (tensile properties and hardness). The optimization of the peroxide content required for the crosslinking of the LDPE/EPDM blends was due by measuring torque and tensile strength. Once the peroxide content was optimized, different blends were obtained by varying the EPDM content. Then they were characterized physically (density, water absorption) and mechanically (tensile properties and hardness). Finally, the blends behavior under the conjugated effect of heat and water was determined at 70 C for 7 days. The obtained results showed that this kind of blending has contributed in improving the performance of regenerated LDPE