Biodegradable Bioplastics

This chapter focuses on the biodegradable subset of bioplastic alternatives, including thermoplastic starch, polylactic acid, and polyhydroxyalkanoate, which offer significant potential for tackling long-term plastic pollution. The majority of plastic ends up in landfills, but a considerable proportion also will escape into the environment, including the oceans. The volume of biodegradable bioplastics produced represents only a very small fraction of global plastics production. The fate of biodegradable bioplastics in natural and engineered environments is poorly understood and potentially problematic. Biodegradable bioplastics, as a “silver bullet” for plastic pollution, are not compatible with this agenda, as they are normally being designed from the outset to be disposed of after one use. A critical question when considering the use of biodegradable bioplastics is what happens to polymers in the environment. Starch-based mulch films have been shown to perform similarly to conventional plastic in terms of agronomic benefit, although control of lifetimes and mechanical properties can be a challenge.