Mechanical Behavior of Gypsum Composites Reinforced with Retama monosperma Fibers

In this pioneering study, Retama monosperma fibers were used in the preparation of a plaster composite dedicated to the field of civil engineering in order to find a substitute for fiberglass as a reinforcement material. Retama monosperma (Rtam) is one of the plant species abundantly available in Mediterranean regions. The localization of fibers at the organic level, the extraction procedure, physical and mechanical properties were studied to compare them with other vegetable fibers currently used in the manufacture of biocomposites. The results obtained show the possibility of improving the mechanical properties of plaster by using the fibers of Retama monosperma. The purpose of this paper is to promote the fibers of Retama monosperma as a building material in civil engineering in order to boost researchers’ interests in this Mediterranean plant.

Towards a theoretical understanding of alkaloid-extract Cytisine derivatives of Retama monosperma (L.) Boiss. Seeds, as eco-friendly inhibitor for carbon steel corrosion in acidic 1M HCl solution

Because of their availability, lower cost, biodegradability, respect for health, environmental standards and their extremely high efficiency [Benmessaoud Left D, Zertoubi M, Irhzo A, Azzi M, Revue: Huiles et extraits de plantes comme inhibiteurs de corrosion pour différents métaux et alliages dans le milieu acide chlorhydrique, J Mater Environ Sci 4:855–866, 2013], the green corrosion inhibitors are currently the most sought after candidates. The ultimate aim of this work is to study the selectivity and reactivity of a series of three molecules, namely Cytisine, Dehydro-Cytisine and N-methyl Cytisine which are the major constituents of Retama monosperma seeds alkaloid extract (AERS) as eco-friendly inhibitors of corrosion of carbon steel in acidic medium HCl (1M), using the density functional theory (DFT) at B3LYP/aug-cc-pvdz levels. Indeed, this alkaloid extract AERS has proven experimentally its corrosion inhibitory power for carbon steel in 1 M HCl even at lower concentration (94.42% at 400[Formula: see text]mg/L). Besides, its adsorption on the steel surface in 1 M HCl solution followed Langmuir’s isotherm [El Hamdani N, Fdil R, Tourabi M, Jama C, Bentiss F, Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies, Appl Surf Sci 357:1294–1305, 2015, doi: 10.1016/j.apsusc.2015.09.159; El Hamdani N, Contribution a la valorisation des parties aériennes de Retama Monosperma, phytochimie, activités antimicrobiennes et propriétés anticorrosives, Universite Chouaib Doukkali Faculte des sciences El jadida, 2015]. Herein, the major aim of this work is to investigate the likelihood of the carbon steel corrosion being inhibited by the protonated species in the aqueous acidic solution. For this purpose, after proving that the most favorable protonation site for protonation was N9, we have evaluated the structural, global and local reactivity descriptors, partial atomic charge in terms of Natural bond orbital (NBO) of the three protonated inhibitors at the level of N9, which are the most stable in the aqueous acidic solution. NBO analysis and the thermodynamic properties such as entropy, enthalpy, heat capacity and Gibbs free energy were also done. In conclusion, it was observed that three protonated molecules showed a high propensity to adsorb to the mild steel surface with a priority of the molecule d-CytN9H+.

Extraction and analysis of polysaccharides from tissues of Retama monosperma branches

Retama monosperma is a fabaceous shrub that colonizes dune sands owing to its particularly important root system at depth and on the surface. It establishes symbiotic associations with rhizobia and thus plays a role in the bio -fertilization of soils. The stem fibers of R. monosperma are an interesting material for industry because of their useful biometric, physical, chemical and structural characteristics. The aim of this study was to complete these data with a biochemical analysis of the cell walls tissues of adult branches of R. monosperma. Cellulose, hemicelluloses and pectins were extracted from cell wall. The weight dosage indicated that cellulose remained the major component of the wall (56% from the crude cell wall and 52% from the delignified cell wall) ahead of hemicelluloses (16% from the crude cell wall and 14% from the delignified cell wall) and pectins (5.6% from the crude cell wall and 5% from the delignified cell wall for water extract pectins and 3% from the crude cell wall and 2.4% from the delignified cell wall for oxalate extract pectins). The colorimetric assay of pectins extracted from lignified cell wall of R. monosperma suggested presence of more uronic acids (14.95µg/mL) than pectins extracted from a delignified cell wall (12.37 µg/mL). Gas chromatographic analysis of hemicellulosic extracts showed the presence of xylose as the major ose (54.7% from the crude cell wall and 46.7% from the delignified cell wall). Pectins were represented by homogalacturonan chains and rhamnogalacturonans 1. Data generated in this study are helpful for valorization of this plant.