Plant-Based Plastics

Researchers recently found a new use for bagasse — the portion of the sugar cane plant that is left after the sugar-bearing juice has been extracted from the cane. Bagasse represents about 90% of the sugar cane mass. Currently, it is mainly burned to fuel generators. But with a little tweaking, it can also be used to manufacture biodegradable food containers.

Previous attempts to use bagasse for this purpose fell short because the product could not withstand contact with liquids. Bagasse is composed of short fibers, giving it little resilience when wet. But when combined with a longer fiber, like bamboo, the long and short fibers interweave and overlap to provide a stronger bond. In addition, when heat is applied (as it is in the hot-press manufacturing process), the lignin in the fibers binds the materials together and produces a water-repelling effect.

The new material is completely biodegradable; when buried in the ground, approximately half of a cup made from the bagasse material had rotted away in a matter of two months. It’s also twice as strong as the plastic typically used to make beverage cups and costs about half to produce, making it ideal for products like coffee cups, straws, and disposable plates.

For more information, contact Hongli Zhu in care of Northeastern University, College of Engineering, 360 Huntington Avenue, Boston, MA 02115or via email at h.zhu@northeastern.edu; or visit https://coe.northeastern.edu/