Abstract
Manufacturing transformation toward a net-zero carbon society demands polymeric composite materials to be reprocessable in circularity in an energy-efficient and stable manner. Recent advancements in vitrimers have bestowed crosslinked polymers like epoxies with reprocessability, opening a path for the circular manufacturing of thermosets. However, (re)processing of mechanically robust vitrimers such as epoxy vitrimers typically requires high temperatures and long processing times, which cause degradation and compromise efficient recyclability. Here, we report a simple design of dynamic polyurea/epoxy (DPE) vitrimers and their carbon-fiber-reinforced polymers (CFRPs) with exchangeable disulfide crosslinks, which overcome such intrinsic limitations. Compared with conventional epoxy vitrimers, the DPE vitrimer exhibits 6 times faster bond rearrangement and ∼40°C lower reprocessing temperature, which enables full recovery of the mechanical strength throughout 6 reprocessing cycles, while the conventional vitrimer lost ∼63% of strength. Moreover, the CFRPs prepared with the DPE vitrimers exhibit facile multi-cycle processability and repairability by thermoformation.
| Original language | English |
|---|---|
| Article number | 101036 |
| Journal | Cell Reports Physical Science |
| Volume | 3 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 21 2022 |
Funding
The work was supported by the US Department of Energy , Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office (VTO). We would like to thank Dr. Jiancheng Luo for the initial discussion on the choice of an isocyanate building block. The work was supported by the US Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office (VTO). We would like to thank Dr. Jiancheng Luo for the initial discussion on the choice of an isocyanate building block. T.S. and M.A.R. conceived the idea. T.S. and Z.Z. designed the experiment. Z.Z. conducted the experiments. Z.Z. S.K. C.C.B. B.L. N.G. E.L.-C. and A.H. performed materials characterizations. Z.Z. S.K. M.A.R. and T.S. wrote and revised the manuscript. C.C.B. E.L.-C. and A.K.N. edited the manuscript. All authors read and edited the manuscript. The authors declare the following competing financial interest(s): a patent application has been submitted based on this study. T.S. M.A.R. and Z.Z. US provisional application serial no. 63/334261.
Keywords
- carbon fiber
- composites
- dynamic covalent bonds
- processability
- recycling
- thermoset
- vitrimer
