Organocatalyzed ring opening polymerization of regio-isomeric lactones
| Autor: | Jules Stouten, Stefaan M. A. De Wildeman, Marie A. F. Delgove, Christian A. M. R. van Slagmaat, Jurrie Noordijk, Katrien V. Bernaerts, Aleksandra Wroblewska |
|---|---|
| Přispěvatelé: | Biobased Materials, RS: FSE Biobased Materials, Sciences, RS: FSE AMIBM, AMIBM, RS: FSE Sciences |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Polymers and Plastics
Bioengineering CATALYSTS 02 engineering and technology DECALACTONE 010402 general chemistry PHOSPHORIC-ACID 01 natural sciences Biochemistry Ring-opening polymerization Catalysis AMPHIPHILIC BLOCK-COPOLYMERS L-LACTIDE chemistry.chemical_compound Polymer chemistry METHYL Reactivity (chemistry) CYCLIC ESTERS Bifunctional POLYESTERS chemistry.chemical_classification EPSILON-CAPROLACTONE Chemistry HYDROGEN-BONDING ORGANOCATALYSTS Organic Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences Ceiling temperature Monomer Polymerization 0210 nano-technology Lactone |
| Zdroj: | Polymer Chemistry, 11(21), 3573-3584. Royal Society of Chemistry |
| ISSN: | 1759-9954 |
| Popis: | Organocatalysts are increasingly gaining attention for the ring opening polymerization (ROP) of lactones due to numerous advantages. In this work, the goal is to expand the scope of catalysts for the ROP of alkyl substituted caprolactones: a mixture of beta,delta-trimethyl-epsilon-caprolactones (TMCL). Several organocatalysts were evaluated, with a focus on bifunctional organophosphorus catalysts including two novel categories, namely phosphonic acids and phosphinic acids. The effects of initial monomer concentration, temperature, catalyst loading and catalyst type on the monomer conversion at equilibrium and the reaction kinetics were addressed. The ceiling temperature of TMCL is 302 degrees C in bulk and 34 degrees C at 1 M, as determined experimentally. During polymerization, higher conversion and reaction rates were observed for the most substituted lactone ( proximal lactone). This difference of reactivity between the two regio-isomeric lactones was greater for lower reaction temperatures. Density functional theory (DFT) calculations on the ring opening of the lactones demonstrated that the difference of reactivity can be attributed to a lower enthalpic contribution of the proximal lactone making the ring opening of this lactone more energetically favored. The difference in calculated Gibbs free energy was found to increase with lower temperature. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|