In situ preparation and scale-up of microencapsulated butyl stearate in poly(urethane-urea) single-shell for low-temperature thermal management applications

The intended objective of this research is to introduce the microencapsulation parameters of butyl stearate in poly(urethane-urea) single-shell under in situ polymerization conditions and its validation by scale-up fabrication for thermal energy storage applications. While N-(2-hydroxyethyl)ethylenediamine and isophorone diisocyanate were used for fabrication of the urethane and urea bearing single-shell material, butyl stearate was chosen as the fatty acid ester-based phase change material inside the core for the thermal applications at low temperatures. The research reports the influence of the surfactant type and concentration on encapsulation efficiency and demonstrates the scale-up of the fabricated composites for validation of the facile procedure. While GC–MS analyses were conducted to test the leakage-free property of the composites, the thermal data have been presented with necessary statistical calculations by using differential scanning calorimeter and thermogravimetric analyzer. Proton nuclear magnetic resonance and Fourier transform infrared spectroscopy were used for chemical characterization of the synthesized phase change material and composites. Additionally, scanning electron microscope imaging was used to understand the influence of the surfactant type on the morphology of the composites. The reported data reveal that the optimization and scale-up studies provided high efficiency microencapsulation of the fatty acid ester-based PCM (butyl stearate) as a promising shape-stabilized phase change material for thermal regulation, space cooling/ventilation applications and heat pumps.