Hybrid functional N-octadecane@melamine-formaldehyde-boric acid microencapsulated phase change material for building energy management and flame retardancy

The main purpose of synthesizing boric acid-formaldehyde shelled microencapsulated phase change material (mPCM) in this study is to produce a cheaper, mechanically and thermally tough material with fire retardant properties. For this reason, a boric acid formaldehyde prepolymer was first synthesized and then combined with phase change material (n-octadecane in this work) in a suspension medium and converted into microencapsulated materials with a curing agent. Boric acid-formaldehyde shell mPCM was produced for the first time in this work, and the shell structure was proven for the mechanical constraint, remarkable thermal characteristics, and flame retardancy. FTIR Spectroscopy, DSC, Polarised Optical Microscopy, Particle Size Analyzer, and Thermogravimetric Analysis instruments were operated for thermal energy and performance characteristics of the mPCM. Microparticles had suitable particle size morphology (unimodal and less than 225 mu m at 90 %), energy storage density consistent with the composition ratio, flame retardancy (27 LOI for the shell), and considerable thermal endurance capacity (remarkably high shell degradation temperature). In the second part of the study, mPCMs were evaluated in cementitious composites. Additionally, due to their density advantage, the produced structures can be applied in cement mortar more easily than the other mPCMs. It has been observed that the addition of mPCM in cement mortar samples does not have a considerable effect on material properties and has the potential to increase thermal comfort in buildings.