Do biodegradables have their PLAce?

A recent BBC article discussed the merits of both biodegradable and compostable plastics in addressing our throwaway culture. Both the UK and Canada are set to ban single-use plastics in the next two years and alternatives that will not accumulate in landfill or the environment need to be found and established, fast.

With our existing infrastructure, a lot of currently available alternatives to petroleum based plastics are simply replacing one form of plastic waste with another. This is demonstrated within compostable packaging standards – which say that industrial scale composting conditions must be able to break-down the material over 12 weeks leaving pieces no bigger than 2mm. Industrial compositing conditions are far more forcing than household waste, boosting the need for collection schemes to enable such changes. If the plastics don’t make it to the correct conditions then they may simply break down into smaller pieces that are not “composted” and cause more problems than the original.

Its important to remember however that, as with chemical recycling, biodegradables and compostables have their place. The two are distinctly different, and would therefore need differing standards in their widespread use. These materials can particularly play a part in invisible waste streams, such as adhesives and plastic films. These receive less attention due to their difficulty to recycle and relatively smaller size but are a large contributor to our plastic waste problem.

Chemical recycling – all its cracked up to be?

Over 50% of plastic produced each year is discarded after a single-use, contributing to the never ending stream of plastic waste both in the UK and internationally. While plastic remains the best material for the job in a lot of cases, we need to make smart choices with how this is reused, recycled or biodegraded. The GML is an active participator in the RE3 project aiming to address some of these issues in the UK. Currently most of this waste stream is recycled mechanically, which requires separation and is not compatible with all material input – could chemical recycling be the answer we’ve all been looking for?

A collaborative effort amongst US universities recently reported the upcycling of single-use polyethylene into high quality petroleum products in the latest effort to add value to the 40bn tonnes of plastic waste projected to be present on Earth by 2050. This breakthrough has been covered a lot in the news and the BBC asked Mike for his thoughts. Its important to realise the forcing conditions that are still required in this process, with temperatures of 300 °C for over 30 hours, while platinum is by no means a cheap metal to employ. However, chemical recycling, if it can be optimised, could become a key part of the recycling infrastructure in the UK. The process may avoid the need for sorting our waste streams, saving money and time – while converting this mix to a useful feedstock with real value.

Well Done Waitrose!

Waitrose is leading the way in the UK supermarkets’ pursuit of cutting single-use plastic waste with their “Unpacked” trial in Oxford.

Packaging has been removed from 75% of produce, with more fragile items sold in cardboard punnets, while flowers are wrapped in recyclable craft paper or in fibre-based pots rather than the classic cellophane wrap and plastic pots. Customers are then offered compostable or reusable cotton bags to put other produce in.

The packaging revelation continues further through the store with refill dispensers for certain dried foods! Not only does this minimise packaging waste – but also facilitates a cut down in food waste, where customers take only what they need, rather than what is available/cheapest.

While this presents a great shift towards increasing the value of plastic materials through their reuse, it is vital that safety standards are maintained. Plastic packaging helps to preserve certain produce for longer, while lots of loose products increases the risk of food contamination. It may also take consumers a while to adapt and therefore the right behaviour must also be encouraged with regards to actually reusing the containers and bags available – not using more each time they shop.

“Unpacked” is the latest in a line of initiatives lined up by the store, with their recent pledge to cut out black plastic, which isn’t widely recycled in the UK. While last year they stopped handing out disposable coffee cups in store.

Rheological Characterisation of Poly(FLP) Networks

Congrats to Utku and Meng for their new Macromolecules paper! This work further investigates the rheological properties of our novel polymeric Frustrated Lewis Pairs.

The original styrene-FLP copolymers were studied, as were newly synthesised FLP-MMA copolymers. The networks formed upon addition of a DEAD linker behave as non-covalent supramolecular assemblies with a high temperature dependence. Increasing crosslink density resulted in a more solid-like material, as did the switch to a more flexible MMA backbone as a result of more facile chain rearrangement.

Group Transfer Polymerization of Methacrylates

Great work by Dan in his new Macromolecules paper! The paper details our work in developing novel titanium-amino-phenolates complexes for the radical polymerisation of methyl methacrylate. The polymerization is possible without the need for a co-catalyst or activator and gives good control over molecular weight, as expected with a controlled radical polymerization. These systems however proceed via a unique bimetallic group transfer process, providing insight into titanium-mediated radical reactions and polymerizations.

Compostable Sales Soar!

With the UK throwing away 2.5bn coffee cups a year, the “latte levy” of 25p on plastic disposable cups was welcome progress on government policy addressing single-use plastic waste. The EU has also announced plans to ban single-use plastics – ranging from plastic straws to a reduction in food and drink packaging.

For some businesses, such as the Houses of Parliament, this has drawn their attention towards compostable products as an alternative for food packaging. It was recently announced that Vegware has seen its sales increase 50% since the discussions around disposale cups and straws started! However the compostable packaging requires special disposal at composting plants and is not compatible with ordinary waste dumps. Vegware has pledged to collect waste from businesses it supplies to try and solve this problem – but commercial composting is currently very regional in the UK.

Landfill taxes can encourage a shift towards recyclable and compostable packaging options. However, as pointed out by the Scottish Green Party and Friends of the Earth Scotland, its important that we don’t think about replacing one single-use plastic with another. Compostable packaging has a place, especially with UK-wide composting coverage, but only where a disposable option is truly needed.

“If you were going to a festival you should have a reusable cup for your beer, but for your falafels, you should probably use Vegware.”

GML at Greater Manchester Green Summit

Following on from the GML joining Manchester’s RE3 project, Prof. Shaver represented the University of Manchester and the Henry Royce Institute at the recent Greater Manchester Green Summit! Greater Manchester has ambitious plans to be a carbon neutral city by 2032 and to eliminate avoidable plastic waste by 2020, lots of positive discussion was had at the summit surrounding these aims.

Mike outlined the scale of the problem with plastic waste, with 40 billion tonnes of plastic waste projected to be present on Earth by 2050. Greater Manchester is well placed to provide a sustainability model for others to follow – with attitudes moving away from going “plastic-free” resulting in increased food waste, and instead towards focusing on using better materials and using current ones in a smarter way.

While development of new materials including biodegradable and self-repairing polymers is key, organisations and individuals need to take responsibility for their plastic use. The way we deal with this generated waste also needs to be managed more effectively in considering what we can and should biodegrade, reuse and recycle. Collaboration between academia, industry and the public sector is vital in this respect, with projects such as the RE3 facilitating such collaboration.

Take a look here for more details on the summit.