When a spider is spinning its web, its silk starts out as liquid and quickly turns into a solid that is, pound for pound, sturdier than steel. They manage to create these impressive materials at room temperature with biodegradable and environmentally friendly polymers. Materials scientists at Carnegie Mellon are studying these processes to better understand the ways biological systems manipulate polymers, and how we can borrow their techniques to improve industrial plastic processing.

One unique quality of polymers is that their molecules can have different shapes or “architectures,” and these shapes can have a big impact on their material properties and recyclability. Polymer chains can form molecular strings, mesh-like networks, or even closed rings.

A new discovery about how ring-shaped polymers behave offers the potential to enable new ways for polymer scientists to design more sustainable materials. A team of researchers from Carnegie Mellon, Sandia National Laboratories, and the University of Illinois at Urbana-Champaign (UIUC) has conducted the largest simulation to date on this type of polymer and confirmed theoretical predictions, finding that the ring polymers spontaneously solidify into glass when their chains become sufficiently long.