Polyurethane/n-Octadecane Phase-Change Microcapsules via Emulsion Interfacial Polymerization: The Effect of Paraffin...

Area of Science:

• Materials Science
• Polymer Chemistry
• Energy Storage

Background:

• Organic phase-change materials (PCMs) offer high latent heat capacity for thermoregulation but suffer from leakage issues in their liquid state.
• Developing encapsulated PCMs is crucial for practical applications in energy storage and thermal management systems.
• Polyurethane encapsulation provides a robust solution to contain liquid PCMs and improve their thermal reliability.

Purpose of the Study:

• To encapsulate the organic PCM n-Octadecane within polyurethane capsules.
• To investigate the effect of n-Octadecane feeding on capsule morphology, shell properties, and thermal energy storage.
• To evaluate the performance of the encapsulated PCMs as a thermoregulating additive in paint.

Main Methods:

• Oil-in-water emulsion polymerization of polymethylene polyphenylene isocyanate and polyethylene glycol.
• Confocal microscopy and Fourier-transform infrared spectroscopy for verifying encapsulation.
• Differential scanning calorimetry (DSC) to determine latent heat storage capacity and actual PCM content.

Main Results:

• Successful encapsulation of n-Octadecane in polyurethane shells was confirmed.
• Capsule size ranged from 9.4 to 16.7 µm, with shell thickness decreasing from 460 to 220 nm as n-Octadecane feeding increased.
• Latent heat storage capacity increased from 50 to 132 J/g, with actual n-Octadecane content reaching 67%.

Conclusions:

• Polyurethane-encapsulated n-Octadecane effectively addresses leakage issues of organic PCMs.
• Increased n-Octadecane content leads to enhanced latent heat storage properties.
• The developed encapsulated PCMs show potential as thermoregulating additives for paints.