Influence of the use of recycled polyols obtained by glycolysis on the preparation and physical properties of flexible polyurethane

摘要

Polyurethanes (PUs) represent one of the most important groups of plastics, and so the increasing quantity of wastes makes their recycling an urgent task. The general purpose of PU chemical recycling is to recover constituent polyol, a valuable raw material. Among the suitable processes, glycolysis in two phases allows better quality products. The objective of this work is the evaluation of the option to apply the recovered polyols to obtain PU with identical characteristics to the starting raw material, and so several foaming tests were carried out according to the evaluation method employed in free expansion foaming of conventional flexible slabstock foams. To achieve this objective, a formulation recipe for flexible foams was selected, in which the raw polyol was totally or partially replaced for recovered polyol. The foaming formulations were modified because of the different amount of active hydrogens in the recovered polyols and the virgin polyol. Amounts up to 50% could be applied without relevant changes in rising profiles and the physical properties of the foams. The foams were characterized, and according to its appropriate characteristics they can be employed in the same applications where a commercial one made with raw polyol is used. (c) 2008 Wiley Periodicals, Inc.