New Chemical Recycling Technology for Regeneration of Polyester and Polyamides

PGR-P-2040

Key facts

Type of research degree: PhD
Application deadline: Ongoing deadline
Project start date: Wednesday 1 October 2025
Country eligibility: International (open to all nationalities, including the UK)
Funding: Competition funded
Source of funding: University of Leeds
Supervisors: Dr Bao Nguyen
Additional supervisors: Ningtao Mao
Schools: School of Chemistry

<h2 class="heading hide-accessible">Summary</h2>

53m tonnes of fibres globally and 1m tonnes of textiles in the UK are consumed annually, of these, the majority end up in landfill or incineration, and currently only 1% of used textiles are recycled back into textile manufacture. More than 60% of fibres used in making apparel are polyester. However, these fibres are rarely recycled; thermoplastic synthetic plastics degrade during the melting process3. Toxic and hazardous solvents (including ionic liquids) used chemical recycling can prevent fibres from being up/recycled. In recent years, deep eutectic solvents (DES) have been demonstrated as viable alternatives for ionic liquids in the glycolysis and hydrolysis of polyester to monomers. The potential of which broadens the possibility of commercially viable recycling and upcycling of textile polymers. This project will present a solution to the problem of synthetic textile waste. Successful applicants will investigate a novel technology of incomplete hydrolysis of polyester fibres in an optimised DES formulation. This will produce oligomers (10-20 units, which can be reassembled into polymers), rather than monomers which are formed by existing technologies (e.g., Worn Again), to engineer a novel polyester recycling technology for the regeneration of recycled polyester into high performance polyester fibres. The project will explore a vast variety of DES for dissolving polyester fabrics and employ modern statistical techniques such as Design of Experiment (DoE) and Machine Learning (ML) to help optimise the DES formulations for the polyester dissolving and fibre formation processes. As well utilising world-leading School of Chemistry facilities, the project will incorporate process development expertise and flow equipment within the Institute of Process Research and Development (iPRD) and the Leeds Institute of Textiles and Colour. Successful applicants will join a cohort of LITAC-funded scholars, who meet regularly in quarterly Collaboration and Knowledge Exchange (CAKE) sessions, which are designed to prepare researchers with skills relevant to their academic career. Topics covered include - speaking and presentation skills, a guide to funding poster exhibits, and how to maximise the use of a travel allowance.

<h2 class="heading">How to apply</h2>

Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the Planned Course of Study section the you are applying for PHD Chemistry FT, in the research information section that the research degree you wish to be considered for is New Chemical Recycling Technology for Regeneration of Polyester and Polyamides as well as <a href="https://eps.leeds.ac.uk/chemistry/staff/4205/prof-bao-nguyen">Professor Bao Nguyen</a> as your proposed supervisor and in the finance section, please state clearly the funding that you are applying for, if you are self-funding or externally sponsored. If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below). As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability. Applications will be considered on an ongoing basis. Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed. Please note that you must provide the following documents in support of your application by the closing date of Monday 6 January 2025 if applying for the China Scholarship Council-University of Leeds Scholarship, Monday 3 February 2025 if applying for Leeds Doctoral Scholarship or Tuesday 1 April 2025 for Leeds Opportunity Research Scholarship. If you are applying with external sponsorship or you are funding your own study, please ensure you provide your supporting documents at the point you submit your application: <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> </ul>

<h2 class="heading heading--sm">Entry requirements</h2>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

<h2 class="heading heading--sm">English language requirements</h2>

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<h2 class="heading">Funding on offer</h2>

Self-Funded or externally sponsored students are welcome to apply. UK – The <a href="http://phd.leeds.ac.uk/funding/138-leeds-doctoral-scholarship-2025-faculty-of-engineering-and-physical-sciences#:~:text=Key%20facts&text=One%20Leeds%20Doctoral%20Scholarship%20is,rata%20for%20part%2Dtime%20study.">Leeds Doctoral Scholarship</a> (closing date: Monday 3 February 2025) and <a href="https://phd.leeds.ac.uk/funding/234-leeds-opportunity-research-scholarship-2022">Leeds Opportunity Research Scholarship</a> (closing date: Tuesday 1 April 2025) are available to UK applicants. <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds. Non-UK – The <a href="https://phd.leeds.ac.uk/funding/48-china-scholarship-council-university-of-leeds-scholarships-2021">China Scholarship Council - University of Leeds Scholarship</a> is available to nationals of China (closing date: Monday 6 January 2025). The <a href="https://phd.leeds.ac.uk/funding/73-leeds-marshall-scholarship">Leeds Marshall Scholarship</a> is available to support US citizens. <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds. You will be responsible for paying the overtime fee in full in your writing up/overtime year (£320 in Session 2024/25), but the scholarship maintenance allowance will continue to be paid for up to 6 months in the final year of award. Important: Please note that that the award does not cover the costs associated with moving to the UK. All such costs (<a href="https://www.leeds.ac.uk/international-visas-immigration/doc/applying-student-visa">visa, Immigration Health Surcharge</a>, flights etc) would have to be met by yourself, or you will need to find an alternative funding source. Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.

<h2 class="heading">Contact details</h2>

For further information about this project, please contact Professor Bao Nguyen by email to <a href="mailto:B.Nguyen@leeds.ac.uk">B.Nguyen@leeds.ac.uk</a> For further information about your application, please contact PGR Admissions by email to <a href="mailto:maps.pgr.admissions@leeds.ac.uk">maps.pgr.admissions@leeds.ac.uk</a>