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Microencapsulation of imidazole curing agents by spray‐drying method using W/O emulsion
Author(s) -
Shin Min Jae,
Kim Jin Gon,
Shin Jae Sup
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.35490
Subject(s) - materials science , curing (chemistry) , emulsion , epoxy , vinyl alcohol , differential scanning calorimetry , chemical engineering , imidazole , composite material , polymer chemistry , nuclear chemistry , chemistry , polymer , organic chemistry , physics , engineering , thermodynamics
Imidazoles were microencapsulated for the latent curing of the epoxy resin— imidazole system. Using polycaprolactone as the wall material, the microcapsules were formed by spray‐drying method using water/oil (W/O) emulsion. Poly(vinyl alcohol) was used as the emulsion stabilizer. The imidazoles used in this study were imidazole and 2‐methylimidazole. The amount of imidazoles in the microcapsule was measured using elemental analysis. The permeability of the microcapsules was measured in ethanol, and the shelf life of the microcapsules was also studied for the epoxy resin. The curing behavior of these microcapsules to epoxy resin was examined using a differential scanning calorimeter. In the curing reaction, the microcapsule of imidazoles exhibited delayed kinetic behaviors compared to pure imidazoles. And the curing times were estimated at 150 and 180°C using an indentation method. These microcapsules of imidazoles exhibited a long shelf life. When comparing the previous method in which simple dichloromethane solution was used for spray‐drying, finer microcapsules were formed using the W/O emulsion. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012