CO2-based polycarbonate polyols as strength enhancers in flexible foams

von Peter Shepard, Scott Allen, Christopher Simoneau, Irma Campara, Aisa Sendijarevic, Vahid Sendijarevic

The use of traditional polycarbonate polyols in flexible foam formulations has been quite limited to date, likely due to challenges around both compatibility/processing and cost/performance tradeoffs. Novomer has recently developed unique polycarbonate polyols based on CO₂ and propylene oxide, which address these challenges and deliver enhanced performance to flexible polyurethane foams at a cost competitive with existing polyether polyols. The high carbonate density in Novomer’s polypropylene carbonate (PPC) polyols delivers a number of performance enhancements to traditional slabstock, resilient moulded, and visco-elastic foam formulations. In studies of all three foam types, the addition of 10 – 20 % PPC to an existing B-side (polyol) formulation can more than double load bearing properties such as compression force deflection (CFD), increase tear strength by over 75 %, and significantly increase tensile strength. In order for foam producers to realise these benefits in an efficient and practical manner, the challenges inherent to polycarbonate polyols of high viscosity and moderate compatibility with polyether polyols must be overcome. Novomer has achieved both of these goals by creating polyether/polycarbonate block copolymers, which have significantly reduced viscosity, excellent compatibility with polyether polyols, and still deliver the performance improvements made possible by the unique PPC polyol backbone.