Self‐Hybrid Biocomposites Based on Luffa cylindrica and Polyethylene

ABSTRACT In this study, self‐hybrid biocomposites based on Luffa cylindrica fiber and linear medium density polyethylene in a powder form were prepared by thermal compression at 190°C. This fiber was utilized to take advantage of its natural structure and was used directly and in a pulverized form. Five types of biocomposites were prepared and characterized: (1) natural structure of Luffa fiber (longitudinal, and transversal), (2) untreated Luffa fiber powder of different sizes (mesh 40, 50, 70 and 100), (3) Luffa fiber treated with 2% sodium hydroxide, (4) hybridization of the natural structure of Luffa fiber with 10% of 100 mesh fiber powder (longitudinal, and transversal) and (5) self‐hybridization of 10% of Luffa fiber 1:1 mesh 50:100. A morphological characterization was performed, followed by mechanical characterization in tension, flexion, and impact. Thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy analyses were performed on selected samples to determine the relation between structural and macroscopic properties. The outstanding mechanical properties observed are obtained from a combination of the different structures combined together in terms of fiber size, content, and treatment, as well as the concept of self‐hybridization by using both the mat natural structure with smaller fibers. In general, the best mechanical properties are obtained for hybrid biocomposites, leading to a 50% increase in flexural modulus and a 100% increase in tensile modulus compared to the matrix.