High strength in combination with high toughness in robust and sustainable polymeric materials

Strong and tough fibers Dragline spider silk is known for its combination of strength and toughness, but this combination has been hard to replicate in synthetic fibers. Liao et al. electrospun polyacrylonitrile- co -methyl acrylate fibers modified with a small amount of poly(ethylene glycol) bisazide (PEG-BA) (see the Perspective by Fox). After collecting the electrospun yarn, it was annealed under tension that both aligned the small fibers and cross-linked them together via the PEG-BA. As hoped, the overall properties were comparable to those of spider silk. Science , this issue p. 1376 ; see also p. 1314