Preparation and characterization of composites
Composites were prepared by open mold hand lay-up method at room temperature. Aluminum mold (200mm×200mm×3.2mm) was used to cast the composites plates (show in Figure. 2a). Composites were prepared using epoxy matrix and four different particle sizes of cuttlebone particles as reinforcement. Initially required mass of reinforcement and matrix material for particular weight fraction were calculated based on the required volume of the cast. The reinforcement and epoxy resin were mixed slowly for 15 minutes to achieve an even distribution of reinforcement particle in the matrix. Then hardener was added into the mixture at the ratio of 10:1 ( resin : hardener). Again it was mixed for 10 minutes in gentle manner to avoid air bubble formation. The mold releasing agent was applied on the mold before pouring the mixed on to the mold. Then the mixture was poured from one corner of the mold and allowed to cure for 8 hours, composite plates were removed from the mold (show in fig. 2b). the plates were cured at 800C for 3 hours in a hot air oven, during this process, uncured residual monomers were cured completely. Similarly, composites were prepared at five different weight ratios (3%,6%,9%,12% and 15%) and three different particle size (˂300µm,˂150µm, and ˂75µm) . Tensile test specimens were cut down from the prepared composite sheet using water jet cutter. Tensile test was conducted according to the ASTM D-638 standard using universal testing machine (UTM-Instron-3366) with a load cell capacity of 10 kN and crosshead speed of 5mm/min. Figure. 2C shows different tensile specimens before and after the test. Morphological studies was done on the broken surface of the tensile specimen by scanning electron microscopy (JEOL JSM-6380LA, Japan) to see the interaction between the cuttlebone particles and matrix. Before SEM analysis samples were gold sputtered using JFC 1600 auto fine coater, JEOL, Japan.