Recycled polyurethane elastomers: a universal adhesive

The practical application of the glycolysis mixture of polyurethane wastes is reported. It was found that in the presence of 4,4′-diphenylmethane diisocyanate (MDI) both the separated upper phase of the glycolysis mixture and the complete two-phase reaction mixture could be used as components of the urethane adhesive mixtures for bonding woods, metals, plastics, glass, ceramics, paper and leather. The adhesive properties were determined by tensile-cutting, cutting- and bending strengths, as well as peel resistance measurements. The method to use the complete glycolysis mixture is also reported. The reaction mechanism of bonding is also discussed.