The development of degradable polymeric materials such as degradable polyurethane or polyurea has been much highlighted for resource conservation and environmental protection. Herein, we demonstrate a facile strategy of constructing… Click to show full abstract
The development of degradable polymeric materials such as degradable polyurethane or polyurea has been much highlighted for resource conservation and environmental protection. Herein, we demonstrate a facile strategy of constructing mechanically strong and tough poly(urea-urethane) (PUU) thermosets that can be degraded under mild condition by using triple boron-urethane bonds (TBUB) as cross-linkers. By tailoring the molecular weight of the soft segment of the prepolymers, the mechanical performance can be finely controlled. Based on the cross-linking of TBUB units and hydrogen-binding interactions between TBUB linkages, the as-prepared PUU thermosets have excellent mechanical strength of ∼40.2 MPa and toughness of ∼304.9 MJ/m3 . Typically, the PBUU900 strip can lift a barbell with 60 000 times of its own weight, showing excellent load bearing capacity. Meanwhile, owing to the covalent cross-linking of TBUB units, all the PUU thermosets show the initial decomposition temperatures over 290 °C, which are comparable to those of the traditional thermosets. Moreover, the TBUB cross-linked PUU thermosets can be easily degraded in mild acid solution. The small pieces of PBUU sample can be fully decomposed in 1 M HCl/THF solution for 3.5 h at room temperature. This article is protected by copyright. All rights reserved.
               
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