Effects of Crab Shell and Charcoal Reinforcements on the Mechanical Properties of Polyester Matrix Composites

Abstract

Composites are produced when two or more materials are used to give combination of properties that cannot be attained otherwise. This study aims to use crab shell and charcoal reinforcements to enhance the mechanical properties of polyester composites and decrease the environmental pollution caused by the agro waste. In this study, 5 – 25 wt. % of 100 g of grounded charcoal and crab shell with an average particles size of 150 µm were used for polyester matrix composites. Flexural strength, impact resistance, hardness and elastic modulus tests were carried out on the developed samples. The microstructure of the samples revealed a uniform distribution of the reinforcements within the polymer matrix with different morphology of the biocomposites. The results showed that the greatest flexural strength value of 361.37 MPa was obtained at 25 wt. % and the highest Brinell hardness number (BHN) was 118.27 at 20 wt. %. However, the highest modulus of elasticity was 335.63 MPa at 15 wt. % reinforcement with crab shell reinforced and was 308.64 MPa with charcoal reinforcements at 20 wt. %. Furthermore, the highest impact energy was 5.49 J for crab shell and 5.31 J for charcoal reinforced polyester composite. The development of the biocomposites of these materials will decrease the environmental pollution and improve the properties of the polyester matrix composites for engineering applications.

Optimal Formulation of Hybrid Polypropylene Composites Reinforced Crab Shell Flour and Rubberwood Sawdust after Immersing in Different Water Conditions for Applications in Tropical Countries

“…This implies that these factors negatively affected the FS. This finding agreed with Bolasodun et al [45] who concluded that the FS of polyester matrix composites decreased with increasing the crab and charcoal content up to 10 wt% due to poor dispersion of the particulates in the matrix resulting in weak bonding. This result is consistent with the microscopy images of the WPC surfaces as shown in Table 11.…”

“…The result observed that the addition of the CS into the hybrid WPCs led to a decrease in the hardness properties. This is consistent with Bolasodun et al [45] who reported that when the crab shell particles ranging from 5 to 10 wt% were used for reinforcement, the hardness properties of the composites decreased due to the agglomeration of the particulates in the matrix. The surface plot of the output response for the hardness properties is presented in Fig.…”

“…The quadratic regression models for the HN of the hybrid WPCs immersed in seawater with several times are given in Eqs. ( 44), (45), and (46) as below:…”