Hybrid bio-fiber/bio-ceramic composite materials: Mechanical performance, thermal stability, and morphological analysis

Abstract

Hybrid composite materials are becoming more desirable for various industrial applications to enhance sustainability and develop better environmentally friendly green products. This work aims to enhance the synergy of both bio-ceramic eggshell materials and date palm leaflet (DPL) fillers to integrate their advantages in an optimized hybridization manner to enhance their significance in producing novel biomaterials with improved desired mechanical, thermal, and morphological characteristics. Different weight percentages of hybrid green reinforcement (poultry eggshells and DPLs) were utilized in various hybridization ratios (3:7, 5:5, 7:3), (15:5, 10:10, 5:15), and (20:10, 15:15, 10:20) to fabricate 10, 20, and 30 wt% novel biomaterials. The regularly chopped DPLs were immersed in various concentrations of sodium hydroxide at different soaking times to optimize and improve their bonding with the polypropylene (PP) matrix. The mechanical, thermal, and morphological properties of the fabricated hybrid composites were investigated. The results have revealed that certain hybridization ratios could improve the tensile and flexural modulus by up to 26 and 11%, respectively. According to the thermogravimetric analysis and its derivatives, hybridization was also found to have an excellent influence on the thermal stability of the PP matrix. Regarding morphological micrographs utilizing scanning electron microscopy, DPLs exhibited good bonding, whereas eggshell fillers depicted different behaviors of bonding depending on their surface topologies. It was also found that hybridization with higher eggshells had better effects on flexural strength than date palms, regardless of their weight percentages. The 30 wt% hybridization case was found to be capable of improving the modulus of elasticity of composites to 838 MPa and the flexural modulus to 735 MPa, which are suitable for various structural applications and green products.