PPG polyether polyols with DMC technology: towards a more sustainable polyurethane.

Mattresses, cushions, car seats, sponges, protection for fragile parcels, heat and acoustic insulators, floor coverings… though we may not be aware of them most of the time, polyurethanes are probably the most common polymers in our everyday lives.

Polyols are used in the manufacture of polyurethanes – usually polyester and/or polyether polyols, and their unique characteristics are what ultimately determine the final properties of the product in question. Within the field of polyether polyols, PPGs (polypropylene glycol) are very widely used, particularly in CASE applications (coatings, adhesives, sealants and elastomers).

A catalyst is needed for the synthesis of PPG polyether polyols, with KOH (potassium hydroxide) having been the traditional choice. This technology is fairly cheap, but it doesn’t allow for the production of elevated molecular weights, and it generates a higher presence of monol and unsaturated polyols during the process, thus reducing functionality and potentially increasing emissions of volatile organic compounds (VOCs) during the subsequent synthesis of polyurethanes.

By the 1960s, the chemical industry had started to develop polyether polyols using double metal cyanide (DMC) as a catalyst instead of KOH, but it wasn’t until the start of the 21st century that this technology was perfected and showed itself to be the most environmentally-friendly option, as it generates close to no by-products and reduces odours.

What’s more, thanks to the possibility of producing higher molecular weights with lower hydroxy (OH) values, it is possible to reduce the amount of isocyanate required for the production of polyurethanes, with subsequent reduced environmental impact and cost savings, thus offering a high-quality end product thanks to the physical-chemical properties of these polyols, which are even suitable for food contact use.

Two years ago, Grupo Barcelonesa established an exclusive distribution agreement for the Spanish market with polyether polyol manufacturer PCC Rokita. This industrial group, located in Poland and with German investment, is known for its excellent product quality and innovative capacity, having developed its own DMC technology, which Grupo Barcelonesa now offers.