Microencapsulation of a fatty acid with Poly(melamine–urea–formaldehyde)

• Published in: Energy conversion and management 2014-04, Vol.80, p.382-390
• Main Authors: Konuklu, Yeliz, Paksoy, Halime O., Unal, Murat, Konuklu, Suleyman
• Format: Article
• Language: English
• Subjects: Analyzers; Applied sciences; Binary surfactant system; Differential scanning calorimetry; Encapsulation; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fatty acid; Fatty acids; Fourier transforms; Latent heat; Microcapsule; Phase change material; Scanning electron microscopy; Surfactants; Thermal energy storage; Thermal stability; Transport and storage of energy
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2014.01.042

•Decanoic(capric) acid microcapsules were prepared with different capsule wall materials.•The one-step in situ polymerization technique was used.•Leakage-free, thermally stable microPCMs was prepared with Poly(MUF).•Influence of different surfactants on encapsulation and thermal properties reported. The main purpose of this study is to obtain leakage-free, thermally stable decanoic acid microcapsules (microPCMs) for thermal energy storage applications. Decanoic acid (capric acid) is an environmentally friendly fatty acid since it is obtained from vegetable and animal oils. MicroPCMs were prepared with different capsule wall materials via a one-step in situ polymerization technique. The properties of microencapsulated PCMs have been analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), Fourier transform infrared (FTIR) spectra analysis and particle size analyzer. The microPCMs prepared using Poly(urea–formaldehyde) (PUF) exhibit higher heat capacities and the microPCMs prepared using Poly(melamine–formaldehyde) (PMF) exhibit higher thermal stabilities. In order to obtain microPCMs with better properties such as suitable latent heat and better heat resistance at high temperatures, we microencapsulated decanoic acid with Poly (melamine–urea–formaldehyde) (PMUF). Furthermore, the effects of surfactants on microPCMs with PMUF were investigated by SEM, a particle size analyzer, DSC, and TGA. The results show that the binary surfactant system was a suitable emulsifier for this process. We determined that the melting temperature was close to 33°C, the latent heat storage capacity was about 88J/g, and the mean particle diameter was 0.28μm for microPCMs with PMUF. We recommend decanoic acid microencapsulated with PMUF for thermally stable and leakage-free applications above 95°C.