Not necessarily. Whether a polymer is biodegradable depends ultimately on its structure, rather than how it is produced. While most Class A and Class B biopolymers happen to be biodegradable, only a few Class C polymers (e.g., PBS and PBAT) are.
Biopolymers are actually not biodegradable, as they are claimed to be, and thus will not solve the plastics crisis.
Biopolymers and bioplastics do not directly address the accumulation of plastic waste; biodegradable plastics and plastic recycling are the primary means to address waste. The primary advantage of bioplastics is the use of renewable biomass as raw material instead of non-renewable oil and gas.
Bioplastics, even if biodegradable, do not degrade fast enough under normal conditions, and composting facilities must be used.
Biodegradability is only a side benefit of some biopolymers. Biopolymers, as well as conventional plastics, vary considerably in terms of speed of degradation. PHAs, for example, degrades very fast under environmental conditions, whereas PLA and PBAT require the heat of industrial compost. Furthermore, too fast degradation would undermine a plastic product’s usefulness.
Bioplastics are only good for packaging applications and would not replace all conventional plastics.
Applications for biopolymers have diversified significantly, especially with the developments of Class C bio-based polymers. The proportion of bio-based polymers produced for packaging in 2020 was 47%, only slightly higher than 40% for conventional plastics.
The production of biopolymers takes up much agricultural land and impacts human and animal food production.
In 2019, 0.016% of the world’s total agricultural land was used to produce feedstocks for biopolymers. It means that, even if all plastics produced today were bio-based, and even assuming the land area used increases proportionally with production volume, the proportion of farmland used would not exceed 2%.
