Entropically Driven Macrolide Polymerizations for the Synthesis of Aliphatic Polyester Copolymers Using Titanium Isopropoxide
| Autor: | Marc A. Hillmyer, Angelika E. Neitzel, Annabelle Watts, Adrian G. Amador |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Organic Chemistry Dispersity 02 engineering and technology Polymer 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Inorganic Chemistry Polyester chemistry.chemical_compound chemistry Polymerization Polymer chemistry Materials Chemistry Copolymer Titanium isopropoxide 0210 nano-technology Glass transition Glycolic acid |
| Zdroj: | Macromolecules. 52:2371-2383 |
| ISSN: | 1520-5835 0024-9297 |
| Popis: | Thermal and mechanical properties of sustainable aliphatic polyesters can be tuned through the synthesis of copolymers. The synthesis of two 14-membered macrolides are reported: a cyclic tetraester with alternating lactic acid (LA) and 3-hydroxypropionic acid (3HP) units and a cyclic diester with alternating glycolic acid (GA) and 2-methyl-1,3-propanediol (2MD) units. Ring-opening transesterification polymerization (ROTEP) of these macrolides to yield poly(LA-stat-3HP) and poly(GA-alt-2MD), respectively, were found to be modestly endothermic (ΔHp° = 2.0 and 0.5 kJ mol–1, respectively) and endoentropic (ΔSp° = 27 and 23 J mol–1 K–1, respectively). Inexpensive and nontoxic titanium isopropoxide Ti(Oi-Pr)4 functions as an active catalyst for these entropically driven ROTEPs, achieving high conversions (>90%) in under 1 h. The polymerizations exhibit control over molar mass with dispersity values |
| Databáze: | OpenAIRE |
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