Reprocessable thermosetting polyurethane/lignin composites with light-triggered shape memory effect
발표자
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초록
내용
Thermosetting PU/lignin composites were prepared by crosslinking NCO terminated PU prepolymer, obtained from the reaction of semicrystalline polyethylene glycol (PEG, Mn=4,000) with excess hexamethylene diisocyanate (HDI), with a lignin as crosslinking agent. It was revealed that dynamic phenol-carbamate bonds was formed via reaction of NCO of PU prepolymer with phenol of lignin, which endow the PU/lignin composites thermal reprocessability with well recovered mechanical properties. Owing to the action of lignin as a photothermal agent along with the role of semicrystalline PEG as reversible switching segment, the PU/lignin composites exhibit good shape memory behavior under direct heating above Tm or NIR irradiation. This novel recyclable and photo-responsive shape memory PU/lignin composite can be potentially applicable for the design of remote-controllable actuators, wearable devices, and biomedical devices.