Highly Impact‐Resistant Silk Fiber Thermoplastic Composites

Abstract

Silk fibres combine good stiffness and strength with a very high strain to failure and are as such highly promising to realize composites with high impact resistance. It is shown that to realize this potential it is quite beneficial to employ matrix materials of high strain to failure, particularly thermoplastic matrices. High impact resistance is thus achieved, well above values for the pure matrices. Below the glass transition temperature of the thermoplastic matrix, the impact energy absorption decreases. The adhesion between fibre and matrix also plays a significant role; lower adhesion typically increases the low‐velocity penetration impact resistance, due to the spread of damage. Finally, the fibre architecture is pivotal; when a woven fabric is used which is unbalanced in strength, the impact resistance reduces in correspondence with the weakest material direction. A quasi‐isotropic lay‐up has a lower capacity for deformation than a balanced woven configuration which likely explains the observed lower penetration impact resistance.This article is protected by copyright. All rights reserved.