High Selectivity and Activity Catalysts to Deliver Sustainable Polymers

Lead Research Organisation: University of Oxford

Abstract

Polymers are highly versatile materials and essential in our everyday lives with applications in every sector. Modern medicine, consumer products, packaging, construction, textiles, electronics, and transportation are all dependant on polymers. The majority of materials used to make plastics are derived from unsustainable depleting petrochemical or fossil fuel sources. Manufacturing of plastics has increased exponentially over the past several decades, and the pervasive nature of plastic has led to intense pollution globally.
Recent efforts in research have focussed on sustainable plastics made from renewable or bio-derived resources, such as plant extracts or carbon dioxide, but matching mechanical and thermal properties to fossil fuel derived polymers has been challenging. Properties can be modified and improved by making block copolymers, this is where two chemically distinct segments of monomers are attached to each other. Current research has focussed largely on polymers with either 2 or 3 block segments. In 2014, a new type of catalysis was discovered which enables facile preparation of block copolymers with precise sequencing of the monomers and allowing multi-block sequences. These block polymers had good properties and were easily recycled or biodegraded after use, however, further property improvements are required.
This project addresses both better polymer properties and catalysis used in manufacturing. The catalysis will be applied to compare properties of block polymers featuring different monomer sequences, including tri-, penta- and hepta-block polyesters and polycarbonates. The project will uncover the optimum manufacturing methods, polymer chemistry structure-performance relationships, and assess recycling options. In a second phase, polymer ionomers will be investigated by addition of a very low quantity of earth-abundant metal ions (e.g. zinc, magnesium, or calcium ions) to provide transient chain cross-linking and moderate properties. Polymer properties, like strength, toughness, stiffness, and elasticity will be tested for all polymers made. The end-of-life options through re-processing, recycling, and degradation will also be assessed. Through a collaboration with the engineering department, modelling of the materials will be employed to further optimise the mechanical properties. In the final part, the self-healing properties of the polymers will be assessed by understanding dynamic covalent interactions, i.e. where reversible metal ion coordination chemistry is exploited.
Ultimately, this project aims to utilize renewable resources to produce sustainable plastics with thermal and mechanical properties that match current commercial polymers. This project falls within the EPSRC 'manufacturing the future' research area.

Planned Impact

The primary impact of the OxICFM CDT will be the highly-trained world-class scientists that it delivers. This impact will encompass both the short term (during their doctoral studies), the medium term (subsequent employment) and ultimately the longer timescale defined by their future careers and consequent impact on science, engineering and policy in the UK.

The impact of OxICFM students during their doctoral studies will be measured by the culture change in graduate training that the Centre brings about - in working at the interface between inorganic synthesis and manufacturing, and fostering cross-sector industry/academia working practices. By embedding not only from larger companies, but also SMEs, we have developed a training regime that has broader relevance across the sector, and the potential for building bridges by fostering new collaborations spanning enormous diversity in scientific focus and scale. Moreover, at a broader level, OxICFM offers to play a unique role as a major focus (and advocate) for manufacturing engagement with academic inorganic synthetic science in the UK.

From a scientific perspective, OxICFM will be uniquely able to offer a broad training programme incorporating innovative and challenging collaborative projects spanning all aspects of fundamental and applied inorganic synthesis, both molecular and materials based (40+ faculty). These will address key challenges in areas such as energy provision/storage, catalysis, and resource provision/renewal necessary to enhance the capability and durability of UK plc in the medium term. To give some idea of perspective, the output from previous CDTs in Oxford's MPLS Division include two start-up companies and in excess of 30 patents.

It is not only in the industrial and scientific realms that students will have impact during their timeframe of their doctorate. Part of the training programme will be in public engagement: team-based challenges in resource development/training and outreach exercises/implementation will form part of the annual summer school. These in turn will constitute a key part of the impact derived from the CDT by its engagement with the public - both face-to-face and through electronic/web-based media. As the centre matures, our aspiration is that our students - from diverse backgrounds - will act as ambassadors for the programme and promote even higher levels of inclusion from all parts of society.

For our partners, and businesses both large and small in the manufacturing sector, it will be our students who are considered the ultimate output of the OxICFM CDT. Our programme has been shaped by the need of such companies (frequently expressed in preliminary discussions) to recruit doctoral graduates who can apply themselves to a broad spectrum of multi-disciplinary challenges in manufacturing-related synthesis. OxICFM's cohort-based training programme integrates significant industry-led training components and has been designed to deliver a much broader skill set than standard PhD schemes. The current lack of CDT training at the interface of inorganic chemistry and manufacturing (and the relevance of inorganic molecules/materials to numerous industrial sectors) heightens the need for - and the potential impact of - the OxICFM CDT. Our students will represent a tangible and valuable asset to meet the long-term skills demand for scientists to develop new materials and nanotechnology identified in the UK Government's 2013 Foresight report.

In the longer term, the broad and relevant training delivered by OxICFM, and the uniquely wide perspective of the manufacturing sector it will deliver, will allow our graduates to obtain (and thrive in) positions of significant responsibility in industry and in research facilities/institutes. Ultimately we believe that many will go on to be future research leaders, driving innovation and changing research culture, and thereby making a lasting contribution to the UK economy.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023828/1 01/04/2019 30/09/2027
2714578 Studentship EP/S023828/1 01/10/2022 30/09/2026 Chang Gao