Characteristics of a silk fibre reinforced biodegradable plastic

Silk fibre is one kind of well recognized animal fibres for bio-medical engineering and surgical operation applications because of its biocompatible and bio-resorbable properties. Recently, the use of silk fibre as reinforcement for some bio-polymers to enhance the stiffnesses of scaffolds and bone fixators has been a hot research topic. However, their mechanical and biodegradable properties have not yet been fully understood by many researchers, scientists and bio-medical engineers although these properties would govern the usefulness of resultant products. In this paper, a study on the mechanical properties and biodegradability of silk fibre reinforced Poly (lactic-acid) (PLA) composites is conducted. It has been found that the Young's modulus and flexural modulus of the composites increased with the use of silk fibre reinforcement while their tensile and flexural strengths decreased. This phenomenon is attributed to the disruption of inter- and intra-molecular bonding on the silk fibre with PLA during the mixing process, and consequent reduction of the silk fibre strength. Moreover, bio-degradability tests showed that the hydrophilic properties of the silk may alter the biodegradation properties of the composites compared to that of a pristine PLA sample. (C) 2010 Published by Elsevier Ltd.