DC pole | Wartość | Język |
dc.contributor.author | Grobelny, Zbigniew | - |
dc.contributor.author | Golba, Sylwia | - |
dc.contributor.author | Jurek-Suliga, Justyna | - |
dc.date.accessioned | 2019-01-15T10:29:36Z | - |
dc.date.available | 2019-01-15T10:29:36Z | - |
dc.date.issued | 2019 | - |
dc.identifier.citation | “Polymer Bulletin” (Vol. 76, iss. 1 (2019), s. 3501–
3515) | pl_PL |
dc.identifier.issn | 1436-2449 | - |
dc.identifier.uri | http://hdl.handle.net/20.500.12128/7785 | - |
dc.description.abstract | Various alkali metal salts were applied as initiators for ε-caprolactone anionic ringopening
polymerization in tetrahydrofuran at room temperature. It was observed that
potassium methoxide (MeOK), potassium isopropoxide (i-PrOK) and potassium
tert-butoxide (t-BuOK) nonactivated or activated by 18-crown-6 (18C6) initiated
polymerization mainly by deprotonation of the monomer. In the case of potassium
hydride (KH), its basicity increased with the ability of the ligand for cation complexation.
For example, KH without ligand or with weak ligands for K+
as 12C4
reacted exclusively by ring opening. However, in the presence of strong ligands,
as 15C5, 18C6 or cryptand C222, basicity of H−
increased with the ability of the
ligand for cation complexation. In the last case, ~ 32% of the monomer was deprotonated.
In these systems, gaseous H2
evolved during the initiation. Deprotonation of
the monomer by some initiators resulted in macromolecules with reactive aldehyde
group or lactone ring as starting groups. They took part in the reaction with potassium
alkoxide active centers of growing chains leading to the formation of branched
poly(ε-caprolactone)s. Sodium hydride (NaH) was inactive, but in the presence of
15-crown-5 or 18-crown-6 initiated polymerization exclusively by ring opening.
MALDI-TOF mass spectrometry supported with 13C NMR and SEC was used for
analysis of the polymers obtained. Mechanism of the studied processes was proposed
and discussed. | pl_PL |
dc.language.iso | en | pl_PL |
dc.rights | Uznanie autorstwa 3.0 Polska | * |
dc.rights.uri | http://creativecommons.org/licenses/by/3.0/pl/ | * |
dc.subject | Anionic polymerization | pl_PL |
dc.subject | Alkali metal salts | pl_PL |
dc.subject | ε-Caprolactone | pl_PL |
dc.subject | MALDI-MALDITOF mass spectrometry | pl_PL |
dc.title | Mechanism of ε‑caprolactone polymerization in the presence of alkali metal salts: investigation of initiation course and determination of polymers structure by MALDI‑TOF mass spectrometry | pl_PL |
dc.type | info:eu-repo/semantics/article | pl_PL |
dc.relation.journal | Polymer Bulletin | pl_PL |
dc.identifier.doi | 10.1007/s00289-018-2554-0 | - |
Pojawia się w kolekcji: | Artykuły (WNŚiT)
|