With more and more attention focused on the effects of climate change, interest in bioplastics — which are produced from renewable biomass materials such as plant starch and vegetable fat — has grown considerably. Bioplastics can also be produced from recycled traditional plastics, which although based on petroleum, don’t add to climate change. Why? Because they already have!
Better yet, most bioplastics are biodegradable, in either oxygen or non-oxygen-based environments. Compare this to petro-based polymers, which are virtually indestructible, even after having been buried or submerged for decades.
The most common sources of biomass materials are agricultural byproducts, such as starches, cellulose and biopolymers, which would simply go to waste if not utilized.
Applications for bioplastics include food packaging, pots and pans, bags, trays, and fresh produce containers. Bioplastics are also ideal for soft drink and milk bottles.
But bioplastics are also appropriate for non-disposable applications, such as cell phone casings, carpets, insulation car interiors, fuel lines, and plastic piping. Some bioplastics have even been used for conducting electric current. However, these so-called bioplastic wires are not biodegradable.
Medical implants made of bioplastics actually dissolve in the body, which can save patients a second operation to remove them — much like sutures which are designed to be absorbed by the body over time. Mulch films can also be produced from starch polymers and can be used for a variety of purposes in agriculture. One of their chief advantages is that they don’t have to be gathered up after use on farm fields.
Starches currently make up the most widely used bioplastic, comprising about 50 percent of the bioplastics supply. In fact, starch is suitable for pharmaceutical applications, because it is able to absorb liquid, and thus quickly break down in the stomach. Sorbitol and glycerine can also be added so the starch can be processed thermo-plastically. The characteristics of the resulting bioplastics can be tailored to specific drug needs by adjusting the amounts of these additives.
More could be said about the utility and versatility of bioplastics. Undoubtedly, much more will be said — and done — in the years to come.