题名：Malleable and thermally recyclable polyurethane foam

摘要：Thermosetting polyurethane (PU) foams, which cannot be recycled economically and efficiently due to their permanently crosslinked structures, have caused significant environmental concerns as well as serious waste of the PU resources after service. To better service sustainable development of PU foam industry, herein, we report malleable PU foams that contain a dynamic disulfide bond. The disulfide exchange reaction under heat enables the PU foam to rearrange the network topology, imparting malleability and thermal processability. The disulfide containing PU foams (PUSFs) exhibit similar appearance and physical properties to common PU foams and were fabricated using conventional foaming technology without any modification. The PUSFs can be easily recycled into PU films through thermal compression molding. The recycled PU films show excellent and tunable mechanical properties depending on the compositions of the original malleable PU foams. Furthermore, the PU film recycled from PU foam with well-designed composition can be further reprocessed for several times without obvious loss in mechanical proprieties and change in chemical structures. This investigation provides a novel methodology to recycle and reuse of PU foams and is expected to promote the sustainable development of PU foam industry.

全文链接：https://pubs.rsc.org/en/content/articlelanding/2021/gc/d0gc03471a