Bio-Based Composites for Light Automotive Parts: Statistical Analysis of Mechanical Properties; Effect of Matrix and Alkali Treatment in Sisal Fibers

Abstract

Composites based on virgin and recycled polypropylene (PP and rPP) reinforced with 15 wt% sisal fibers, with and without alkali treatment, were prepared by compression molding in a mat composed of a three-layer sandwich structure. The sisal was characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The composites were characterized according to physical and mechanical properties. Additionally, a factorial experimental design was used to statistically evaluate the mechanical properties of the composite. The FTIR and XRD indicated the partial removal of amorphous materials from the surface of the sisal after alkali treatment. The composites’ density results varied from 0.892 to 0.927 g·cm−3, which was in the desirable range for producing lightweight automotive components. A slight decrease in the hardness of the pure rPP and rPP composites in relation to the PP was observed. The water absorption was higher in rPP composites, regardless of the chemical treatment. Moreover, the impact resistance of PP and its composites was higher than the values for rPP. Statistical analysis showed that the alkali treatment was a significant factor for the hardness of the rPP and PP composites, and that the addition of the sisal layer was relevant to improve the impact resistance of the composites.

Characterization of Thermo-Mechanical and Chemical Properties of Polypropylene/Hemp Fiber Biocomposites: Impact of Maleic Anhydride Compatibilizer and Fiber Content

“…The impact strength results demonstrate that the impact resistance of the 0-100-0 sample in this study, measured at 24.32 ± 5.61 KJ/m 2 , as consistent with the literature findings [ 15 , 21 , 96 ]. However, the impact strength decreased as the amount of hemp fiber added to the formulations increased compared to pure PP.…”

“…The incorporation of natural fibers in biocomposites has demonstrated significant benefits, providing improved properties and reducing environmental impact when compared to conventional composites. This growing trend in the use of natural fibers is in line with the global push towards a more sustainable economy and the industrial adoption of green materials [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

Cotton incorporated Poly(lactic acid)/thermoplastic Starch Based Composites Used as Flexible Packing for Short Shelf Life Products

“…A few bands in the 1500-1200 cm -1 region to both CH 2 deformations and C-O-H bending vibrations, and intense bands in the 1200-900 cm -1 region are attributed to the stretching modes of C-O and C-C vibrations. The bands from 800 to 700 cm -1 represent the contributions from two crystalline forms of cotton cellulose, in which the type of cellulose is associated with the plant's origin and can directly influence the mechanical properties of cotton [59][60][61][62] .…”

Amazon Natural Fibers for Application in Engineering Composites and Sustainable Actions: A Review

“…The authors mentioned the need to investigate other parameters to achieve the specified requirements. Silva et al [274] evaluated the performance of polyester matrix composites reinforced with different fibers in impact and bending tests. For comparison, they used raffia, jute, mallow, piassava, and sisal fibers as reinforcements in similar compositions.…”

“…In addition, its use contributes to the preservation of the environment, as piassava is a native plant and its sustainable extraction promotes the Based on the results obtained, the authors observed that piassava fibers have high resistance compared to other fibers such as mallow, raffia, and jute, although their performance was slightly lower than the composite with sisal fibers. Among all natural fibers, sisal is one of the most resistant, if not the most resistant natural fiber among the species [273,274].…”