Polyurethane foams degradation products

A good example of such a continuous moulding process that incorporates Foam Film technology is a system developed for the production of industrial vehicle carpets. These products are usually made out of a sandwich of two or more layers of different materials. Individually, they provide different features aesthetics and function (a textile carpet or a synthetic mat), sound deadening (a layer of polyurethane foam) and protective (a cheap layer to protect the foam from moisture and degradation). 

Troev et al. (see, e.g., [80,81]) degraded polyurethanes (microporous elastomers or flexible foams) via exchange reactions between urethane groups and alkoxy groups of phosphonic or phosphoric acid derivatives using dialkyl phosphonates or trialkyl phosphates. The potential application of the oligomeric liquid products is similar to that of the polycarbonate degradation products [29], i.e., for flame retardant formulations and polymer modification. 

Polyurethane materials are extremely versatile in that it is possible to produce a large variety of structures which range in properties from linear and flexible to crosslinked and rigid. The crosslinked PURs are thermosets, which are insoluble and infusible and therefore cannot be reprocessed by extrusion without suffering extensive thermal degradation. At present, the main sources of recyclable waste are flexible PUR foams and automobile waste. Waste and scraps of these materials may consist of 15-25% by weight of total PUR foam production. 

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