For most applications, biodegradable plastics are a nuisance!
The development and introduction of biodegradable plastics is no more than a cheap excuse to delay plastics circular design and application
For the vast majority of plastic objects reduction of plastic waste means designing the plastic so that its end-of-life phase is foreseen beforehand
This is a major new task. Take laminates, materials with several layers, often polyethylene, aluminium and paper, designed to attain all properties required for packaging milk, fruit juices etc.: containment, barrier, appearance. Recycling laminates is a nightmare, and even incineration is a substandard solution as the aluminium just melts. But new laminates with just two layers are available and are much easier to handle in recycling. With dedicated efforts from science, industry and policy makers, these could swiftly penetrate the market
Researchers and engineers should never introduce new plastics without an accompanying supply chain concept – and they should develop chain concepts for existing plastics, if doable at all
The second task in the reduction of plastic waste is as daunting as the first one: recycling plastics from mixed waste streams
Recycling companies will of course prefer ‘clean’ plastic return streams that consist of just one plastic. In an industrial setting, this can be done without too much effort. Clean waste streams can also result from schemes that involve the general public, with an effective deposit scheme like for PET bottles. But there is only so much that can be done in this area, there will remain a mixed plastic waste stream that needs to be treated chemically if we do not incinerate it
Recently, chemical researchers developed techniques to treat mixed plastic waste streams by adding so-called compatibilizers.
This makes it easier for researchers to perform chemical reactions on the plastic waste and we should be able to homogenise a variety of polymers with controlled properties.
Chemists can then apply their full arsenal of homogeneous catalysis for the reduction of plastic waste, as they did in breaking down crude oil to small building blocks and reassembling them to new plastic polymers.
Leasing plastic objects instead of buying them could lend a strong incentive to better recycling through a better design. Because the producer continues to be the owner of the product, they have a major stake in designing it ready for reuse or recycling
Finally, the pinnacle of scientific achievement in this field would be to process a complex mixture (like biomass, or mixed plastic waste), and turn it into a new complex mixture with superior properties while retaining complexity all the way