Researchers at the University of Virginia School of Engineering and Applied Science have developed a polymer material that defies traditional trade-offs between stiffness and stretchability, enabling new applications in technology and medicine. The breakthrough, led by Ph.D. student Baiqiang Huang and assistant professor Liheng Cai, has overturned the longstanding belief that stiffer materials must be less stretchable.
The team’s new “foldable bottlebrush polymer networks” are designed to store extra length within their structure, allowing them to ‘decouple’ stiffness and extensibility without sacrificing one for the other. This approach focuses on molecular design of the network strands rather than crosslinks, enabling the material to be both stiff and stretchy.
The foldable design works by having a central backbone that can collapse and expand like an accordion, allowing it to elongate up to 40 times more than standard polymers without weakening. The side chains determine stiffness, making it possible to control stiffness and stretchability independently.
This universal strategy for polymer networks has endless options for designing materials that balance strength and stretchability while harnessing the properties of inorganic nanoparticles based on specific requirements. The breakthrough material is also 3D-printable, opening up new possibilities for wearable electronics, prosthetics, medical implants, and soft robotic systems.
Source: https://scitechdaily.com/engineering-the-impossible-scientists-solve-200-year-old-polymer-puzzle