Melt-processable shape-memory elastomers containing bisurea segments
US12286508B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 24, 2022 |
| Grant date | Apr 29, 2025 |
| Priority date | — |
| Expiry date | Jul 3, 2043 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G2280/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A shape-memory polymer that is melt-recyclable with high processability and little performance loss, in contrast to known Crosslinked semicrystalline shape-memory networks that are capable of storing large amounts of elastic energy with negligible plastic deformation but as thermosets are not easily melt-processed or recycled. In examples herein, catalyst-free isocyanate chemistry is used to prepare two linear poly(caprolactone)s with bisurea hydrogen bonding groups periodically positioned along the main chain. Compared to an entangled poly(caprolactone) homopolymer of similar molecular weight, the segmented poly(bisurea)s exhibit minimal stress relaxation when elastically strained at identical conditions. Furthermore, the materials' single relaxation times indicate chain reptation, and at sufficient temperatures, disentanglement occurs rapidly enough to perform melt-processing. The polymers show excellent shape fixity and recovery before and after shredding, melt-pressing, and annealing into a reprocessed film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.