Fast-Biodegrading polymers

The success of plastics in sectors as diverse as packaging, construction, automotive, electronics, medical and new energies is due to their ability to offer a considerable range of properties, adjustable by varying the chemistry and molecular organization of the polymers. Their technical and economic optimization for each application means satisfying the requirements associated with every stage of their manufacture: shaping, distribution, use and end-of-life. Resistance over time and inertia in relation to the environment are among the qualities most often required.

The property of biodegradability is a feature that concerns the end-of-life stage of products. Sensu stricto, there is no polymer that is not biodegradable... it all depends on the time scale considered. All organic materials (based on the chemistry of organic carbon ( – C-C- and -C-H bonds)) can be progressively degraded by various means (physical, chemical, biological), ultimately leading to molecules as simple as water, carbon dioxide, methane and various minerals (nitrogen, phosphorus, sulfur, etc.), the initial constituents of organic materials, as illustrated by the Carbon Cycle.

Polyethylene, for example, considered by all to be non-biodegradable, is in fact perfectly biodegradable, provided we wait at least 600 years! As the useful life of this polymer is much shorter than the time required for it to biodegrade, we are now witnessing accumulation phenomena that inevitably lead to visual and physical/(bio)chemical pollution, which can be the source of various ecotoxicities. Many polymers have a long biodegradation resistance time (e.g. polyethylene checkout bags), while their use time is extremely short (around 20 minutes in the case of PE bags).

Given the magnitude of the cumulative phenomena involved, researchers are working tirelessly to develop new polymers whose resistance to biodegradation is equivalent to their useful life. Indeed, for certain specific applications, this alternative to recycling or incineration and energy recovery may prove advantageous. This is the case in particular when a composting process can be organized around green waste bags, or when it is preferable from a technical, economic and environmental point of view to leave the material to degrade in the soil, as in the case of agricultural mulching films, for example. The biodegradation kinetics must then be optimized/adjusted so as to match both the functional requirements and the expected end-of-life conditions for the material.

Plastics are widely used today, mainly in the packaging sector. As these materials are used over a very limited period of time, or even an extremely short one in terms of the material's life cycle, it is necessary to improve the biodegradability...