Indian Journal of Advances in Chemical Science, Volume: 9, Issue : 3, August 2021

ISSN No.: 2320-0898 (Print); 2320-0928 (Electronic)

DOI: 10.22607/IJACS.2021.903015

Research Article

Non-isothermal Deblocking Studies of Amine Blocked Isocyanates and their
Validation Using Numerical Simulation Calculations

ABSTRACT

Influences of isocyanate structure, analytical techniques, and heating rate on deblocking reactions were studied. A series of N-Methylaniline blocked isocyanates with different isocyanates were synthesized. Their solid and solution state deblocking reactions were carried out and studied using different analytical techniques as well as different heating rates. The results indicate that isocyanate structure, the effect of heating rate, analytical method, and state of the blocked isocyanate strongly influence the deblocking reaction. Solution state deblocking reaction always occurs at lower temperatures compared to solid-state reactions. Aromatic isocyanate-based blocked isocyanates deblock at lower temperatures compare to aliphatic isocyanate-based blocked isocyanates. The energy of activation (Ea) for deblocking reaction was determined using conversion degree values obtained from Thermo-gravimetric analysis and with the help of Friedmann-Reich-Levi and Flynn–Wall–Ozawa equations. Experimentally determined Ea was validated using numerical simulation calculations.
 

Key words:   Blocked isocyanates, Deblocking, Friedmann-Reich-Levi, Flynn–Wall–Ozawa, Non-isothermal kinetics,
Simulation.

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