Preparation and characterization of n-octadecane @ bio-based polyurea microcapsules

The phase change microcapsules for thermal energy storage have wide applications in various fields. However, only a small portion of the wall materials used for phase change materials are sourcing from biology, which puts a lot of pressure on the environment. In this paper, we prepared a bio-based polyurea microcapsule. It was prepared by the interfacial polymerization method using HMDI as an oily monomer and bio-based 1,5-pentanediamine as an aqueous monomer. The method is convenient and the optimum process conditions for microcapsule preparation were explored experimentally. The results showed that the prepared bio-based polyurea phase change microcapsules present a spherical appearance and uniform size distribution, with an average particle size of 3 μm or more. Under the optimal conditions, the microcapsules with an encapsulation efficiency of 80.9 %, showing a high enthalpy of melting of 194.2 J/g. Compared with the pure n-octadecane, the obtained microcapsules exhibit good heat-resistance. Based on the addition of 1,5-pentanediamine, the obtained microcapsules are environmentally friendly and have better prospects for energy storage. The thermoregulated fabrics were prepared using bio-based microcapsules,which have good temperature regulation and water washing resistance.