600: Catalysis in Poly(hydroxy-urethane) Systems: Rheo-polymerization Testing

Catalysis in Poly(hydroxy-urethane) Systems: Rheo-polymerization Testing

W. M. Milanowska^a, A. M. Fage^b*, U. Förter-Barth^b, D. Wołosz^a, P. G. Parzuchowski^a*

^aWarsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warsaw, Poland

^bFraunhofer Institute for Chemical Technology ICT, Joseph-von-Fraunhofer-Straße 7, 76327 Pfinztal, Germany

^*Corresponding authors: aleksandra.fage@ict.fraunhofer.de, pawel.parzuchowski@pw.edu.pl

Poly(hydroxy‑urethane)s (PHUs) are gaining attention as sustainable alternatives to conventional polyurethanes. Their attractiveness lies in eliminating the use of toxic isocyanates and the potential to implement monomers derived from renewable resources. However, the synthesis of PHUs from bis(cyclic carbonates) and diamines is hindered by the low reactivity of the system. To address this challenge, various approaches, including the use of catalysts to enhance reaction rates, have been explored.

This study focuses on the investigation of amine- and bismuth-based catalysts in liquid PHU systems. The polymerization reaction was conducted using a plate-plate rheometer in rotational mode — a technique referred to as rheo-polymerization. The structure-property relationships of materials were described using FT-MIR and ¹H NMR spectroscopies, as well as oscillatory rheology measurements.

Here, we explore rheo-polymerization as a functional method for small-scale screening of multiple catalysts. Materials, both catalyzed and non-catalyzed, synthesized at a moderate temperature of 80°C, exhibited similar structural characteristics. A comparison between the two catalyst types demonstrated the superior efficiency of Bi-based catalysts over amine-based ones, as evidenced by higher complex viscosity values. Importantly, no by-products, such as urea, were detected in the samples.

The application of bismuth-based organocatalysts offers a novel and promising approach to catalysis in PHU systems. Furthermore, preliminary rheological studies allow for optimizing reaction conditions and assessing system performance before scaling up PHU synthesis, which is crucial for advancing the field.

Acknowledgements: The research has received funding from the European Union’s Horizon research and innovation programs under Grant Agreement No. 101058279 (project SIMPLI-DEMO).