No abstract

No abstract

No abstract

The effect of chemical modification, reinforcement structure and fiber weight ratio on the flexural proprieties of Luffa-polyester composites was studied. A unsaturated polyester matrix reinforced with a mat of Luffa external wall fibers (ComLEMat), a short Luffa external wall fibers(ComLEBC) and a short Luffa core fi-bers (ComLCBC) was fabricated under various conditions of fibers treatments (combined process, acetylat-ing and cyanoethylating) and fiber weight ratio. It resorts that acetylating and cyanoethylating enhance the flexural strength and the flexural modulus. The fiber weight ratio influenced the flexural properties of com-posites. Indeed, a maximum value of strength and strain is observed over a 10% fiber weight ratio. The uses of various reinforcement structures were investigated. The enhancement of elongation at break and the strain values of the composite reinforced by natural mat was proved

Natural fibers as an alternative fiber reinforcement material have significant advantages over glass. Indeed, they are more environmentally friendly, healthier and safer. Their application in polymer composites requires the understanding of their structure and mechanical properties. Other advantages of using the cellulose fibers as reinforcement are their low densities and their non-abrasive aspect. Various natural fibers have been widely used. Others, however, remain of limited use such as in the case of palms. This study aimed at introducing palm fibers to be used as reinforcement in a polymeric matrix enabling production of economical and lightweight composites for load-carrying structures. First, an investigation of the extraction procedures of fibers from folioles and leafstalks of doum palm was undertaken. Secondly, the mechanical behavior of the treated and untreated doum palm fibers was studied to determine their mechanical properties. Finally, we compared the mechanical properties of the different parts of the tree with other natural fibers.

No abstract

The main objective of this paper is the evaluation of the possibility of using a gypsum mortar reinforced with doum palm fibers as thermal insulators in building material. Several composite configurations with three sizes and five-weight ratios (from 0.5% to 2.5%) of doum palm fiber were prepared for mechanical and thermo-physical characterization. Generally, natural fibers are affected by the alkali environment of gypsum mortar. To overcome this problem, doum palm fibers were treated with a NaOH solution of 1% concentration to enhance their resistance against chemical degradation. Chemical treatment of fiber removes some hemicellulose and lignin and tends to make the fiber more homogenous, which enhances fiber–matrix interfacial properties. In addition, the mechanical properties of the specimens were tested after 7 days, 28 days and 1 year of curing in normal conditions. The obtained results show an improvement in the mechanical performance of composites reinforced with treated fibers. In fact, better results were obtained for gypsum mortar reinforced with treated reinforcement seive2 for the value of 1% of fibers. It was also noticed that NaOH treatment has an influence on the thermal conductivities. In fact, the use of treated doum palm fibers as reinforcement in gypsum mortar seems to be an alternative natural material to be used as a thermal insulator material.

No abstract