Materials: Making strong bio-based replacements for plastics

A fabrication method to produce a strong bio-based material, which could be used as a replacement for plastics, is presented in an article published in Nature Communications this week.

Petroleum-based plastics pose challenges for the environment and our health, but replacing them with sustainable bio-based plastics, which have mechanical properties similar to their petroleum-based counterparts, has been difficult. Incorporating small filler particles with uniform orientation into polymers can improve their mechanical properties, but methods to control the orientation of particles in a polymer are not well developed.

Shu-Hong Yu and colleagues describe a process that uses pressure to arrange small particles in a bio-based polymer. Under pressure the thickness of the material is reduced and the particles align. The cellulose-based polymer fills the gap between vertically aligned mineral particles, which form a microstructure comparable to a brick wall. This brick-and-mortar structure gives the material excellent mechanical properties, outperforming many high-performance plastics. The mechanical properties also remain stable at temperatures when common plastics either become brittle or soften. By fabricating a cell phone case, the authors demonstrate that the process can be scaled up and that the material can be easily processed.

This method provides a pathway towards scalable production of high performance all-natural materials, the authors conclude. Developing such processes could be important to facilitate the uptake of bio-based materials in industry and industrial applications.