The Wetsus research theme Biopolymers from Water develops and innovates on methods to produce and recover biopolymers, in particular polyhydroxyalkanoates (PHAs). PHAs are renewable resources that serve as a versatile platform for bioplastics within circular economy systems, with wastewater and organic residual streams as feedstocks. PHA-based bioplastics are inherently biobased and biodegradable for the plastics industry, as well as being recyclable and renewable. Through well-controlled microbial processes, PHA-rich biomass can be efficiently generated and the polymers effectively recovered, enabling circular resource use. However, to step from recovered PHAs into high-value renewable products for industry, the recovered materials must deliver on commercial quality standards – controlled property specifications and materials that are safe and sustainable by design. The entry of ‘waste’ derived PHAs into circular economic supply chains therefore critically depends on methods to systematically control property specifications, and methods to ensure controlled and sufficiently low levels of regulated non-intended added substances (NIAS, i.e. impurities) in the recovered product.
Research challenge
The research challenge is to establish tools to predict and control property specifications of co-polymer blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) due to an expected window of batch-to-batch variability in the recovered PHA thermophysical properties and a requirement to monitor for fate of trace contaminants that must be maintained below regulated thresholds in the final product. Current methods do not adequately link a variability in the polymer production to the requirements of quality in a final PHA product. At the same time, it has been established that property-specifications can be controlled and tuned in the post manipulation of such co-polymer blends, even during the recovery process itself. Risks for NIAS can be related to “in–out” mass balance assessments in the context of the feedstocks, the biological process and the recovery methods. Tools for steering polymer property specifications through applied polymer science and controlling NIAS quality through engineering principles and strategic monitoring are truly a necessary step over the threshold to entering circular economies where waste becomes a resource.
Your assignment
The research is inherently interdisciplinary with emphasis on polymer science, melt processing, property-testing, and chemical engineering. Your work will focus on the formulation of co-polymer blends towards the control of masterbatch bioplastic properties. You will build on established in-house and knowledge centre expertise, methods and protocols, including solution formulation, extrusion and mechanical testing, as well as analyses and protocols such as rheology, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), pyrolysis GC–MS, Fourier transform infrared (FTIR) spectroscopy, high-performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC-MS) and gas chromatography–mass spectrometry (GC-MS). In addition, the project entails hands-on research of PHA recovery both at laboratory and pilot-scales.
This project is part of the newly funded EU project PHACTUS, and you will therefore contribute to key research activities and work closely with our international partners.
Your profile
You hold a master’s degree in chemical engineering, polymer science, or a closely related field, and have demonstrated experience with practical testing in materials science, polymer melt processing, data analysis, modelling and polymer quality characterisation techniques. You have affinity, and interest, in analytical method development, and you enjoy hands-on experimental work. You have a strong self-drive with initiative to explore topics beyond your current expertise, and you are comfortable in multidisciplinary, international, collaborative settings. You are well versed and curious about concepts of structure-property relationships in polymer science, separation techniques in chemical engineering processes, and the use of ‘green’ organic solvents. Written and oral communication proficiency in English is expected.
Keywords: biopolymer blends; structure-property relationships; crystallization; melt-processing; mechanical testing; impurity tracking; analytical tools; production quality control;
Supervisory Team:
University Promotor: prof. Katja Loos, University of Groningen (Faculty of Science & Engineering, Macromolecular Chemistry and new Polymeric Materials).
Wetsus supervisors: dr. Alan Werker (Biopolymers from water theme leader, Wetsus); dr. Raquel Barbosa (Scientific project manager, Wetsus)
Project partners: Biopolymers from water
Only applications that are complete, in English, and submitted via the application webpage before the deadline will be considered eligible.
Guidelines for applicants: https://phdpositionswetsus.eu/guide-for-applicants/
