What is it about?
Polyoxymethylene (POM) is a high-performance plastic used in automotive, electronics, and consumer goods. It is often produced from trioxane, a cyclic molecule made from formaldehyde. While the polymerisation of trioxane has been known for decades, the very first steps—how the ring of trioxane opens and initiates chain growth—remained unclear. In this study, we used in situ infrared spectroscopy and detailed kinetic analysis to uncover the early reaction pathways of trioxane with acetic anhydride in the presence of acid catalysts. We identified key intermediate molecules, such as trioxymethylene diacetate (TOD), and clarified how reaction conditions and catalyst type influence the formation of short-chain oxymethylene diacetates. These insights improve our understanding of how to control polymer growth at the molecular level.
Featured Image
Photo by Sabrianna on Unsplash
Why is it important?
Understanding the molecular details of trioxane ring opening helps improve the design and production of polyoxymethylene, an important technical plastic. This work reveals that both the strength and nature of the catalyst significantly influence whether early intermediates are formed directly or through consecutive steps. These findings not only enhance our fundamental knowledge of polymer initiation but also suggest new pathways to tailor low-molecular-weight oxymethylene diacetates, which may serve as fuel additives or chemical intermediates. The combination of in situ spectroscopy and mechanistic modelling provides a robust framework for studying other polymer systems.
Perspectives
This was a particularly challenging and rewarding study. Unravelling the chemistry of trioxane polymerisation required navigating a system with very few spectroscopic handles—overlapping NMR signals and poorly soluble products made analysis difficult. Identifying and quantifying key intermediates demanded both persistence and precision, especially when distinguishing similar species in real time. Despite these obstacles, we made significant progress in understanding the early stages of polymer growth. It was deeply satisfying to see how the combination of in situ spectroscopy, careful kinetic modelling, and structural characterisation ultimately shed light on a long-standing question. The insights gained here are not only academically meaningful but also relevant for improving the production of high-performance polymers like POM.
Prof. Dr. Thomas Ernst Müller
Ruhr-Universitat Bochum
Read the Original
This page is a summary of: Reaction pathways at the initial steps of trioxane polymerisation, Catalysis Science & Technology, January 2018, Royal Society of Chemistry,
DOI: 10.1039/c8cy01691g.
You can read the full text:
Resources
Contributors
The following have contributed to this page
