Mechanical performance of an animal-based silk/polymer bio-composite

There has been a concern over many years on the usage of existing metallic and ceramic-based biomaterials for implant design and development due to the necessity of conducting operations for patients to remove and maintain implants after they complete their desired functions. Recently, the development of biodegradable polymers like poly(glycolic acid), poly(lactic acid), and their co-polymers etc. have emerged and provided an entirely new concept to tackle this problem as these polymers can be fully or partly degraded or resorbed by the human body, i.e. an extra operation for removing the implants can be avoided, which can highly alleviate the hard feeling of the patients that come from psychological and physiological pressures. Natural fibres have been well recognized as potential micro-reinforcements for the enhancement of mechanical, thermal and structural properties of biodegradable polymer composites, without generating any harmful by-products and adverse effects during their degrading process to the patients. These natural fibers can be mainly classified depending on their origin into two categories; they are (i) plant-based and (ii) animal-based natural fibers, like spider and silkworm silks. Since the last decade, silkworm silks have been used as reinforcements for fabricating bio-composites. However, no comprehensive study, particularly on the correlation between the mechanical properties of the composites, and fiber orientations and configurations has been done to date. In this paper, an in depth study on the mechanical properties of silk/epoxy composites with different fiber contents and orientations, through experimental approach and fractographic examinations will be conducted. Tensile property tests for all silk/epoxy composite samples will be performed. Failure samples will be examined by using scanning electron microscope (SEM) to investigate the failure mechanism of the composites