Contributions to the quaternization description and kinetics illustrated on poly(dimethylaminoethyl methacrylate)
| Autor: | Virgil Barboiu, Gabriela Liliana Ailiesei, Ecaterina Stela Dragan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Tertiary amine Chemistry General Chemical Engineering Kinetics 02 engineering and technology General Chemistry Polymer 010402 general chemistry 021001 nanoscience & nanotechnology Methacrylate 01 natural sciences Biochemistry 0104 chemical sciences Solvent Chemical kinetics Viscosity Polymer chemistry Materials Chemistry Environmental Chemistry Amine gas treating 0210 nano-technology |
| Zdroj: | Reactive and Functional Polymers. 161:104852 |
| ISSN: | 1381-5148 |
| Popis: | Using the effects of solvent polarity observed on the microstructure of reaction products and the viscosity of the reaction medium, the evolution of the polymer chain conformation when the conversion changes, as well as the corresponding reaction kinetics, are formulated to explain the characteristics of the quaternization reaction of poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA), a polymer with flexible side-chains ended by tertiary amine groups. So, the polymeric chain is fully extended in strongly polar solvents regardless of the degree of quaternization (DQ), leading to simple kinetics of the second order. In less polar solvents, the polymer chain has coil conformation, which causes the reaction to take place more on the coil edge, which in turn leads to quaternized block formation and auto-acceleration. Self-acceleration is explained by bringing the unreacted groups to the periphery of the coil by the solvent because it prefers them in the detriment of the reacted groups. The kinetics model for self-accelerated reactions is validated by finding that the fraction of peripheral unreacted amine groups is nearly constant during the entire reaction. Such kinetics could be applied for other polymer analogous reactions when the polymer chains take coil conformation or associate with each other in globules. |
| Databáze: | OpenAIRE |
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