Mechanical and free vibration properties of clamshell particles/polyester composites

In this work, an experimental investigation was implemented to identify the effect of adding clamshell powder (CSP) into the polyester matrix on the tensile and impact properties along with vibration characteristics of the particulate composites towards using eco-friendly reinforcement phase. Different weight ratios of clamshell powder, ranged from 0 to 20 wt%, were loaded into the polyester resin with particle sizes ranged from 25 to 75 μm. Tensile, Charpy impact and free vibration tests were performed to the specimens fabricated from the neat polyester and CSP-filled polyester. The results showed that the inclusion of CSP into the polyester matrix could improve the tensile modulus of the polyester up to 50% when the CSP weight ratio equals to 12%. Meanwhile, the strain-to-failure, tensile and impact strengths showed decreasing trends with increasing the CSP filler content owing to the weak adhesion (bonding) strength between CSP and the polyester matrix. Maximum improvements in the fundamental natural frequency and damping ratio of CSP-filled polyester were 24% (at 12 wt% of CSP) and 21% (at 8 wt% of CSP), respectively. Based on the results, the clamshell powder could be used as a very cheap bio-filler material within the polyester matrix if the high stiffness composites with improved damping properties are required. (paper)