Processable semi-crystalline polymer networks
AssigneesEspci, Centre National De La Recherche Scientifique
InventorsLudwik Leibler, François Tournilhac, Mathieu Capelot
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Abstract
Polymer network composition having a semi-crystalline covalently crosslinked polymer network including exchangeable covalent bonds and crosslinking bonds and at least an exchange reaction catalyst, wherein the number of crosslinking bonds is sufficient for the polymer network to be beyond the gel point and the number of exchangeable bonds is sufficient for the network to relax stresses and/or flow when conditioned at an appropriate temperature. Such compositions are characterized by the fact that the network is able to reorganize by exchange reactions that allow it to relax stresses and/or flow while maintaining network connectivity.
Claims10
Polymer network composition comprising:
- a semi-crystalline covalently crosslinked polymer network comprising polymeric crystallizable fragments selected from polyolefins, polyesters, thermostable aromatics, or mixtures thereof and further including exchangeable covalent bonds designated L, being either main-chain bonds or crosslinking bonds and pending chains comprising reactive group R, wherein
- the number of exchangeable covalent bonds L, nL, is superior or equal to 15% of the number of crosslinking points, nC, in the network
- the number of reactive group R, nR, is superior or equal to 1% of the number of exchangeable covalent bonds nL,
- exchangeable covalent bonds L are ester bonds and reactive groups R are hydroxyl groups, said pending chains comprising reactive group R are capable participating in an exchange reaction with at least one ester bond and the exchange reaction does not liberate a volatile alcohol, the number of hydroxyl functions is superior to the number of pending ester groups and wherein the polymer network comprises beta-hydroxy-ester bridges;
- and
- a transesterification catalyst.
Dependencies are inferred from the claim text.