Mass balance MDI enables foam adhesive for bricklaying

The buildings sector accounts for a significant share of greenhouse gas emissions. Reducing its large-scale environmental impact means more than just making buildings energy efficient for their operating life. As operating efficiency rises, attention is turning to the carbon footprint of the actual construction materials.

We are partnering with the Selena Group, a Poland-based leader in construction chemicals in over 100 markets, to spearhead a shift to fundamentally more sustainable construction materials that offer the same performance as fossil-based alternatives. 

Our joint vision is to meet European Green Deal energy efficiency goals and drive the wider transition to net-zero carbon emissions for the buildings industry by 2050. In fact, our Desmodur® CQ MB mass balance MDI has already enabled Selena to create its enhanced low-carbon Ultra Fast 70 foam insulation for cavities around windows and doors.  

For this project, we focused on creating a more sustainable alternative to replace cement mortar; a raw material that is widely used in the built environment, and one with a high carbon intensity in its manufacturing process.

The challenge here was to create a viable alternative to conventional concrete mortar with a much lower environmental impact. This new option would have to significantly reduce CO₂ emissions, yet fit easily with current building methods, while also offering high adhesion and quick curing times on site.

Using a polyurethane (PU) foam adhesive for bricklaying showed clear potential here, building on our recent experience with Selena on their low-carbon foam insulation. Our Desmodur® CQ MB bio-attributed MDI (methylene diphenyl diisocyanate) offered a low-carbon feedstock for a foam adhesive that could offer easy on-site application at a wide range of temperatures, along with quick curing and a durable bond. This plant-based MDI feedstock could be attributed to the final adhesive product using the ISCC Plus standard, which defines how to track renewable inputs through unified chemical processes. This mass balance MDI offers the same technical performance as fossil-based raw materials.  

Selena Group created their high-performance foam adhesive for bricklaying using our Desmodur® CQ MB low-carbon MDI. This bio-attributed MDI emits 60% less CO₂ ² than fossil-based MDI. What’s more, in a head-to-head comparison, a single 750 ml can of the final product, Tytan Professional® Adhesive for Bricklaying foam, causes 90% less CO₂ emissions than one and a half 25 kg bags of conventional cement mortar. The new product carries ISCC Plus certification, ensuring accurate allocation of the bio-based inputs, and social responsibility³ across the feedstock supply chain.

Beyond emissions reductions, our bio-attributed MDI also gives the final adhesive product other useful advantages: It can be used with high accuracy on a wide variety of brick or construction block materials, from ceramic and silicate to ACC. This level of precision in application also means a higher yield on construction projects than with traditional cement mortars. Importantly, the low-emission adhesive foam also cures twice as fast. Finally, it can be applied on-site in temperatures ranging from -5ºC to +30ºC degrees Celsius, minimizing work losses from extremely low or high temperatures. This low-carbon alternative to concrete mortar is another Covestro contribution to a circular economy and climate neutrality, making the buildings sector more sustainable.