Building for the Future

Polyurethane (PU) is making a key contribution to sustainable development. In the EU alone around 50 million kWh of energy are saved annually through the use of PU insulation materials. What’s more, innovative developments are giving PU even better insulating qualities.

PU nano-foams

The smaller the foam pores, the better PU insulates. Today’s PU typically has pore sizes of 150 μm. Covestro is researching into foams with pore diameters of 150 nm, a mere 1,000th of the current size. This would reduce PU’s thermal conductivity by half. The challenge, however, is that these nanofoams have to be produced using an entirely different technology than today’s rigid foams. Covestro is collaborating with scientists from Cologne University to fine-tune the chemical reaction between the PU raw materials and simultaneous expansion of the tiny foam bubbles in the micro-emulsions. Once this challenge is mastered, a specific degree of thermal insulation could be achieved through PU insulating material that is only half as thick as today’s.

PU-nano foams
PU under the microscope: generally speaking, insulating performance increases as pore size decreases.

CO2 as PU raw material

cardyon™ technology enables carbon capture and utilization, thus turning CO2, a waste greenhouse gas, into a useful raw material that serves as a building block for plastics. Based on this technology, Covestro now offers a range of cardyon™ branded polyols for use in all kinds of polyurethane applications. The use of CO2 in plastics production benefits the environment by reducing the overall carbon footprint and establishing an alternative carbon source beyond fossil hydrocarbons and bio-based raw materials. For more information please visit the cardyon™ page.

Regulations drive fire safety

Although the EU already classifies PU as having “low” to “normal” flammability, work is continuing to enhance its flame retardance properties. The strongest driver is that further tightening of the relevant regulations is expected at any time. Covestro’s polyisocyanurate (PIR) system for metal-faced sandwich panels has much better fire resistance properties than conventional systems and generates much less fumes. Composite systems of this kind are used primarily to construct industrial buildings, such as warehouses, production halls and cold stores. One outcome of this innovative development is that PIR systems can be used as a viable alternative to inorganic materials if the requirements of Smoke Class s1 have to be met (in line with SBI, EN 13823).

In the future, special attention will be devoted to questions of how PU foam reacts to flame in specific end applications, and the degree to which improvements can be achieved in flame retardance by combining PU with other materials. Covestro experts say the possibilities for improvement are endless. That way, PU is sure to remain one of the best insulation materials for buildings.