ABSTRACT
Silks are naturally produced protein polymers synthesized and processed into bers by a variety of insects and spiders [1-5]. e functions of silks include web construction and prey capture (spider webs), reproduction (cocoons), and safety lines (dragline) [5-7]. Silks also exhibit a unique combination of material properties including lightweight (1.3 g/cm3), high strength (up to 4.8 GPa as the strongest ber known in nature), and high toughness with elasticity up to 35% [8]. e toughness of dragline silk is comparable to high-tenacity bers such as Kevlar 49, while elasticity is 4-7 times higher. In addition, silk as a biopolymer is remarkably stable under thermal conditions (up to ~250°C) allowing processing over a wide range of conditions (Table 7.1) [7].
