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RESEARCH PRODUCT
Hydrogen bonds in unpolar matrix — Comparison of complexation in polymeric and low molecular-weight systems
C. AuschraReimund StadlerL. De Lucca FreitasVolker Abetzsubject
chemistry.chemical_classificationPolymers and PlasticsDouble bondChemistryStereochemistryHydrogen bondEnthalpyInfrared spectroscopyPolymerStandard enthalpy of formationCrystallographyColloid and Surface ChemistryHydrocarbonMaterials ChemistryPhysical and Theoretical ChemistryEquilibrium constantdescription
By ene-reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with double bonds, polar 4-phenyl-1,2,4-triazolidine-3,5-dione (phenyl urazole) groups are introduced into unpolar matrices. Hydrogen-bond complexes are formed between two amide-like units. The temperature dependence of complex formation in dilute hydrocarbon medium is obtained from remperature-dependent IR spectra in the region of the C=O stretching vibration. Results obtained for a low molecular-weight model system are compared with modified polybutadienes, where the groups are attached statistically along the polymer backbone. The enthalpy and the entropy of complex formation (ΔH f =−28.6 kJ/mol; ΔS f =−52 J/mol K−1) obtained for the low molecular-weight model prove a dimeric chelate like complex involving two hydrogen bonds. The lower equilibrium constants observed for the groups attached to the polymer are related to additional topological constraints emerging from the polymer backbone.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1991-06-01 | Colloid and Polymer Science |