Seminar 'Designing Polymers for Circularity' by Prof. Minna Hakkarainen

Minna Hakkarainen is Professor in Polymer Technology at KTH Royal Institute of Technology in Sweden. She got her M.Sc. in Polymer Chemistry from University of Helsinki in 1992 and Ph.D. in Polymer Technology from KTH in 1996. Since 2011 she is full professor and since 2012 the Head of Polymer Technology at KTH. She published >270 papers in international journals and co-authored a text book on Applied Polymer Science (Springer). She is Associate Editor for ACS Applied Materials & Interfaces and in Editorial Advisory Board of several international journals such as Biomacromolecules, Polymer Testing and Macromolecular Materials and Engineering.

Main research area: Sustainable biobased, biodegradable and/or recyclable polymers. Design of polymer materials for high performance and mechanical, chemical or biological recyclability by e.g. utilizing dynamic covalent chemistries or degradation triggers.

Prof. Hakkarainen will give a seminar 'Designing Polymers for Circularity' during her visit at Aalto University in December 2025. Prof. Hakkarainen will act as the opponent at the doctoral defence of M.Sc. Zahra Madani that will take place on 05.12.25 at 12.00 in Lecture hall 241 L1 (Vuorimiehentie 1, 02150 Espoo). More information about the defence: TBA

Abstract of the seminar:

Transition from fossil-based to biobased plastics can positively impact our environment. However, in order to make a real difference, materials need to be designed from sustainable resources (biobased and/or recycled) and have managed and sustainable end-of-life. The most suitable end-of-life management option will depend on the type of material and application. Our recent research concentrates on designing polymers with built-in circularity to facilitate mechanical, chemical and/or organic (biodegradation) recycling.1 Here, I will present some examples of how we utilize dynamic covalent chemistries to increase the circularity of linear thermoplastics and for development of covalent adaptable networks (CANs). We have for example designed series of polyester-imines and polyimine-amides with excellent mechanical and thermal properties and facile recyclability starting from lignin-derivable monomers2 or from monomers obtained by aminolysis of PET.3 Some of the resins also included photocurable groups to combine 3D printability by digital light processing with chemical and mechanical recyclability.4,5 Similar strategies were shown valuable for modification of commercial polymer blends and glass-fiber composites to merge performance with circularity.6,7 Recently, we further demonstrated rational molecular design for linear aromatic polyesters with poly(ethylene terephthalate)-like properties.8 Due to the large processing window, i.e. ~200°C difference between thermal decomposition temperature and temperature required for melt-processing, six repeated mechanical recycling cycles were performed without property loss. Furthermore, due to highly accessible ester-functionalities chemical depolymerization back to original monomers was possible under mild condition, followed by repolymerization to material with properties corresponding to those of the virgin material.

[1] C.V. Aarsen, A. Liguori, R. Mattsson, M. Sipponen, M. Hakkarainen. Chem. Rev. 2024, 124, 8473.
[2] S. Subramaniyan, B. Zhang, P.-O. Syrén, M. Hakkarainen. Chem. Eng. J. 2024, 501, 157632.
[3] N. Kasmi, E. Bäckström, M. Hakkarainen. Resour. Conserv. Recycl. 2023, 193, 106974.
[4] Y. Xu, K. Odelius, M. Hakkarainen. ACS Sustainable Chem. Eng. 2020, 8, 17272.
[5] A. Liguori, S. Subramaniyan, J. Yao, M. Hakkarainen. Eur. Polym. J. 2022, 178, 111489.
[6] K. Garfias, K. Odelius, M. Hakkarainen, Adv. Sus Sys. 2025, 9, 2400711.
[7] K. Garfias, I. Odnevall, M. Hakkarainen, K. Odelius, ACS Sustainable Chem. Eng. 2025, 13, 6746.
[8] Y. Han, P. Zhang, H. Zhou, T. Zhao, K. Odelius, M. Hakkarainen. Angew. Chem. Int. 2025, e202421431.

Contact information:

Prof. Minna Hakkarainen
KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Sweden
Email: minna@kth.se