Key Words:POLYMERIZATION; OPPORTUNITIES
Abstract:Despite the great advancements achieved for the chemically recyclable polymers in recent years, it remains as a challenge to develop chemically recyclable polyurethanes from bio-renewable monomers with thermal and mechanical properties that compare with petroleum-based polyurethanes. In this contribution, we present the successful preparation of a series of chemically recyclable polyurethanes from the ring-opening polymerization of bio-renewable alkyl-delta-lactones followed by the tandem polycondensation with diisocyanate and a chain extender. The thermal and mechanical properties of the obtained polyurethanes can be easily tailored by adjusting the molar mass of soft segment, the hard segment content as well as the length of the pendent alkyl group of the poly(alkyl-delta-lactone) polyol precursor. The obtained polyurethanes behave as thermoplastic elastomers with excellent tensile strength and elasticity that compare with commodity petroleum-based polyurethanes. Remarkably, the obtained polyurethanes exhibit extraordinary hydrolytic resistance and remain intact up to 5 months in acidic or basic aqueous solution. The chemical recycling of polyurethanes to recover clean alkyl-delta-lactones with high yield (> 95 %) can be easily achieved by simple heating the materials in bulk under reduced pressure.
Volume:237
Issue:
Translation or Not:no