Preparation, Characterization and Sustained Release Behavior of Isothiazolinone Microcapsules

Waterborne polyurethanes (WPUs) as capsule wall were designed and synthesized with diisocyanate, polyethylene glycol, dimethylpropionic acid and triethylamine. Isothiazolinone microcapsules were prepared by self-emulsifying method. FT-IR, laser particle size analyzer and SEM were used to characterize the isothiazolinone microcapsules. The effects of wall/core mass ratio on the release behavior of microcapsules were studied by UV-vis spectrophotometry and the sustained release kinetics of microcapsules were further studied. The SEM images and particle diameter measurements show that the microcapsules are regularly global particles, the particle sizes are mainly between 91~960 nm, microcapsules between 268~610 nm account for about 84.1% and the average particle size is 460.9 nm; the curve-fitting results show that the release of isothiazolinone in the microcapsules basically accords with the derived diffusion equation, and the diffusion rate constant increases as the wall/core mass ratio reduces. © 2021, Editorial Board of Polymer Materials Science & Engineering. All right reserved.