Regeneration of Polyol by Pentaerythritol-assistedGlycolysis of Flexible Polyurethane Foam Wastes

The aim of this work is to introduce a novel chemical recycling approach forpolyurethane foam wastes which can produce useful chemicals. Flexiblepolyurethane foam was dissolved in a mixture of diethylene glycol (DEG) andpentaerythritol (PE). PER is a useful choice in recycling processes because of its OHfunctional groups and its structural similarity to polyols. Meanwhile, there are severalenvironmental advantages for chemical recycling of polyurethane foam wastes due tothe capabilities of the above method. The trans-esterification process cleaves theurethane structure, producing OH containing chemicals. The product is separated in 2phases which are both useful in the production of new PU foams. The split product wascharacterized by several analytical methods, e.g., chromatography and spectroscopy.Optimum reaction condition and the role of recycled polyol on foam properties wereinvestigated, as well. The solvent system contained DEG/PER as 9/1 ratio. Sodiumhydroxide was used as the catalyst and the optimum reaction time was 4 h. Separatedphases of the product are reusable in polyurethane foam formulation: upper phase inflexible (40%) and lower phase in rigid (30%) foams to obtain desirable physicalproperties in the final product. This method can be introduced as a route for reductionof environmental hazardous materials, while regenerating valuable raw materials