Kinetic and rheokinetic study of dicarboxylic fatty acid chain extension using a dioxazoline coupling agent
✍ Scribed by Yvan Chalamet; Mohamed Taha
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 187 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
A kinetic and rheokinetic study of the condensation reaction of a dicarboxylic fatty acid, Pripol1009 (C36), and a dioxazoline coupling agent (1,3-Phenylene)bis(2-Oxazoline) (OO) was made. The kinetic study showed a similar reactivity of the two acid groups of C36 and also a similar reactivity of the two oxazoline groups of OO. The reaction kinetics can be described using a second-order kinetic model. A kinetic constant k ϭ 16.1 ϫ 10 Ϫ4 mol Ϫ1 s Ϫ1 at 156°C with an activation energy E a ϭ 80.6 kJ mol Ϫ1 was calculated. A rheological evaluation of the reactants and the obtained polymers showed that the reactive system had Newtonian behavior during all the reaction times for shear rates lower than 100 s Ϫ1 . Using this kinetic modeling and measured viscosity evolution of the reactive system at different temperatures, rheokinetic models were proposed for viscosity evolution with the molar mass evolution of the synthesized polymer and the reaction time and conversion. Viscosity evolution of the reactive system during the first 10 min, corresponding to a typical mean residence time in reactive extrusion, were calculated using the proposed rheokinetic model.