Properties of biocomposites from waste seashells and poly(methyl methacrylate)

The paper presents the preparation of biocomposites from waste seashells as reinforcement and poly(methyl methacrylate), abbreviated as PMMA as the matrix. The used seashells belong to the snow‐white Bahamian species of tiger lucine (Codakia orbicularis) from the Island of Coco Cay. Seashells were grinded and homogenized with poly(methyl methacrylate) powder, with the seashell powder content ranging between 2 and 14 wt%, and finally hot pressed. Morphology of prepared composites was analyzed by scanning electron microscopy, and it was determined that the particle distribution was homogenous with no agglomeration. Mechanical properties (microhardness, compressive strength, Young's modulus) of biocomposite materials produced from different amount of waste seashells in poly (methyl methacrylate) were determined and analyzed. The best overall combination of mechanical properties was achieved when 6 wt% of seashell particles below 50 μm size were added to poly (methyl methacrylate).     

Design and development of engineering component using natural rubber biocomposites

The potential usage of natural rubber biocomposites in engineering products was investigated. The engineering product fabricated is a rubber bush which is widely used in the automobile industry. Three different types of rubber: 25 % mol epoxidised natural rubber, 50 % mol epoxidised natural rubber and deproteinised natural rubber reinforced with eggshell powder and oil palm fibres hybrid biofillers were studied. The mould flow simulation was carried out to study the flow of the rubber in an existing mould cavity. A thermogravimetric analysis was carried out on both the eggshell powder and oil palm fibres and it was observed that the eggshell powder is more stable thermally compared to the oil palm fibres. Static test was conducted to study the static stiffness properties. Dynamic test was also conducted to study the dynamic stiffness and the loss angle. The results of the tests showed promising mechanical properties of the 25 % mol epoxidised natural rubber biocomposites. Further research should be conducted on other biofillers that is capable of improving the properties of the rubber to replace the use of carbon black in the 25 % mol epoxidised natural rubber biocomposite.     

Tribological performance of ceramic composites for biomedical applications: A review

Understanding the wear mechanisms of a material subjected to varying loading conditions in various applications is a key to improve the overall performance of the material. Ceramic based composites when implemented as a bearing material under adverse loading conditions, performed very well but despite this clinical success, wear of these articulating surfaces continues to be one of the leading critical issues which need attention as this will influence the ultimate performance of the implant. Before any material can be used in joint arthroplasty, it is imperative to assess parameters that influence the wear performance of implant material as safety and efficacy are the main challenges. This review focuses and brings forth important aspects related to the wear performance of the ceramic-based nanocomposites employed in joint bearings. This review presents a summary of wear rate data associated to bioceramic composite on the basis of past to recent published literature.