Preparation of Phase Change Expanded Perlite and Its Temperature Control Performance

Abstract:

The aim of this paper is to prepare dual low communion fatty acids phase change materials (PCM) with lauric acid (LA) and myristic acid (MA), according to the calculation results of low eutectic phase transition point theory. Using the vacuum absorption method, a eutectic mixture of lauric acid and myristic acid was incorporated with expanded perlite (EP), and the phase change aggregates were encapsulated with appropriate encapsulations. The cross section of phase change aggregate was observed using field emission scanning electron microscopy (SEM). It was discovered that the fatty acids were absorbed into the porous particle inside and adhered to the wall of perlite pore, and the fatty acids steadily existed in the space encircled by paraffin and expanded perlite inside wall. The LA MA eutectic mixture as PCM was confined in the porous EP by a mass fraction of 200%, and it demonstrated that paraffin was effective to encapsulate the LA MA/EP composite aggregates by a mass fraction of 60%, with less than 3% mass loss after the thermal cycle test, and just 4% mass loss after being soaked into the alkali solution. More PCMs can lead to a decrease of effective heat value, a longer temperature delay and a greater cooling extent. The physical and mechanical performances of the PCMs based mortar board can meet the requirements of the standards of building insulation mortar.

Key words:dual low communion fatty acids; phase change aggregate; encapsulation with paraffin