ATIPIC/BPG Technical Academic Afternoon Workshop 2025     

This presentation illustrates various examples demonstrating improved durability of both waterborne and solventborne coatings through the incorporation of aliphatic branched esters in the polymer backbone. VeoVa™ vinyl esters enhance the performance of emulsions across numerous applications, for instance, in wood stains and anti-corrosion coatings. Copolymers from vinyl esters and silane-functional monomers can function as binder for isocyanate-free moisture-curing coatings, serving as viable alternatives to two-component (2K) polyurethanes while maintaining excellent durability. Additionally, the low surface tension of these polymers facilitates their use in applications such as easy-clean surfaces and anti-graffiti coatings. Finally, neo-acid glycidyl and vinyl esters, Cardura™ and VeoVa™ monomers, enhance film appearance and durability of 2K topcoats.

Over the past years the entire chemical industry has been undergoing new or more stringent regulatory changes. For epoxy resins and curing agents, changes in legislation are impacting their classification / labelling or even their use in certain applications. Examples, include the level of solvents, use of catalysts and the limitation of certain raw materials that are part of epoxy or curing agent composition. Volatile Organic Content limitations have led to the increased use of high solids or waterborne systems. Even solvent free systems can be affected by such regulatory changes. More recently, some widely used reactive diluents have been reclassified as reprotoxic cat. 1B. Under the EU CLP rules (Classification, Labelling, Packaging), mixtures (including paint formulations) containing a component with a reprotoxic cat. 1B classification at concentrations of ≥ 0.3 %, need to be classified as reprotoxic, meaning a CMR labelling. This has resulted in a number of epoxy resins adopting the new labelling. All these regulatory changes are challenging. However they can also create opportunities, such as innovation and development of new products, with more benign or no labeling. This paper will present some of the most recent developments for coating and flooring applications.

The shift toward safer, more sustainable polymers requires replacing substances of concern such as bisphenols, which are increasingly restricted due to their endocrine-disrupting effects, especially in consumer-facing coatings. Lignin, a renewable and bio-aromatic alternative, holds great potential but faces challenges due to variability in quality and sourcing. To address this, VITO has developed unique expertise in lignin valorisation, supported by dedicated pilot-scale facilities (PIlar II and LignoValue), a strong patent portfolio, and EU-funded research initiatives. VITO is among the few organizations worldwide producing lignin-based epoxy resins as a sustainable replacement for fossil-based DGEBA (bisphenol-based) systems. Our approach involves transforming lignin through chemical modification and depolymerization into high-performance epoxy resins tailored for  highly or total bio-based coatings. These materials are evaluated using Safe and Sustainable by Design (SSbD) frameworks to ensure both functionality and environmental safety. The goal is to demonstrate that lignin-based epoxies can match conventional performance standards while enabling scalable, bio-based solutions for the coating industry, marking a meaningful step toward a circular and sustainable materials economy.

By using covalent or non-covalent dynamic bonds, network materials can become self-healing and recyclable [1]. The Diels-Alder (DA) reaction between furan and maleimide is of special interest as this leads to thermoreversible covalent networks. This reversibility is based on covalent bond formation being favoured at low temperatures, forming either endo- or exo-cycloadduct, and bond breaking favoured at higher temperatures.
Using a combination of experimental thermal analysis and spectroscopic techniques and simulations developed using an in-house mechanistic model, a full understanding of reversible covalent bond formation or break-up in these systems becomes available [2]. Of specific interest is the influence of vitrification on the reversibility of the networks, as this is unavoidable in thermosets (T_g>>T_application). The fundamental insights obtained rom this combined approach where applied to develop reversible DA networks with the following properties: (i) curable by UV-irradiation allowing for tuneable thermomechanical and self-healing properties, to be employed in photovoltaic modules as self-healing materials [3], and (ii) incorporating lignin as biomass, for the development of a biobased adhesive [4].

References:

[1] Cerdan, K.; Thys, M.; Costa Cornellà, A.; Demir, F.; Norvez, S.; Vendamme, R.; Van den Brande, N.; Van Puyvelde, P.;  Brancart, J., Prog. Polym. Sci. 2024, 152, 101816

[2] Mangialetto, J.; Verhelle, R.; Van Assche, G.; Van den Brande, N., Macromolecules 2024, 57,  10053-10070

[3] Ehrhardt, D.; Mangialetto, J.; Van Durme, K.; Van Mele, B.; Van den Brande, N., Macromolecules 2021, 54, 9960–9977.

[4] Thys, M.; Brancart, J.; Van Assche, G.; Van den Brande, N.; Vendamme, R., ACS Sustain. Chem. Eng. 2023, 11, 17941–17950.