From an environmental standpoint, plastic is a huge problem. In America we use 2.5 million plastic bottles each hour and recycle only 27 percent of them. Discarded packaging and other plastic products are huge contributors to things like oceanic trash islands, garbage patches, plastic eating microbes and other dystopian-sounding environmental phenomena. Though there have been continued efforts to estimate just how much plastic ends up in places outside of our disposal infrastructure, like the ocean, we still don't really know how it is breaking down or where the pieces are all ending up. Even when plastic is recycled (and it often isn't) it can’t be completely re-purposed like other materials, so the process is more accurately called down-cycling. The outlook seems bleak, yet production of plastic is actually on the rise, further evidence that we are acting as though plastics aren’t suffocating our earth or infiltrating the global food chain.
The quest for a durable, biodegradable, easily-molded, environmentally-friendly bioplastic seems like a quixotic one, but a team at the Wyss Institute at Harvard University has developed a bioplastic fabrication process that uses a form of chitin, an abundant and underutilized material found in shrimp shells.
“Most bioplastics are made from cellulose, a plant-based polysaccharide material. The Wyss Institute team developed its bioplastic from chitosan, a form of chitin, which is a powerful player in the world of natural polymers and the second most abundant organic material on Earth. Chitin is a long-chain polysaccharide that is responsible for the hardy shells of shrimps and other crustaceans, armor-like insect cuticles, tough fungal cell walls — and flexible butterfly wings. The majority of available chitin in the world comes from discarded shrimp shells, and is either thrown away or used in fertilizers, cosmetics, or dietary supplements, for example.” -The Wyss Institute
Chitin itself is not a new discovery. What the team at the Wyss Institute accomplished was developing a process for the production of what they call “Shrilk” (shrimp chitin combined with a protein from silk) that can be molded into complex 3d shapes without breaking or shrinking. The resulting bioplastic degrades in about two weeks, actually adding nutrients to soil and allowing plant life to grow, like the black-eyed pea grown by the Wyss team in chitosan-enriched soil.
Laboratory development of bioplastics like Shrilk is encouraging, but the product still faces the daunting transition to large-scale manufacturing. So, although burying discarded yogurt containers in our gardens might not be an immediate possibility, it's nice to know someone is working on it.
Images provided by The Wyss Institute at Harvard University.