Self-healing, reprocessing and sealing abilities of polysulfide-based polyurethane

Polyurethanes are known for their satisfactory mechanical strength, which is highly desired for various applications. Poly (ethyl formal disulfide)-based materials have excellent self-healing ability because of containing abundant exchangeable disulfide bonds, while their strength is relatively low (<0.8 MPa). Combining the advantages of the two materials, in this article, we synthesized self-healable polysulfide-based polyurethanes with a tensile strength of 2.62-5.80 MPa. After healing at 75 degrees C for 24 h or 100 degrees C for 4 h, the tensile strength of a fully cut optimized sample (PSPU-15) recovered to 90.8 and 93.1% of the original value 2.62 MPa, respectively, with the damaged incision disappearing and the sealing integrity fully recovered. Furthermore, the sample PSPU-15 possessed good reprocessing ability, retaining the tensile strength of 2.66-2.40 MPa after repeated processing. These outcomes indicated that polysulfidebased polyurethane is an attractive paradigm towards sustainable industrial applications. (C) 2018 Elsevier Ltd. All rights reserved.