Microencapsulation of Phase Change Materials with a Soy Oil-Based Polyurethane Shell via Pickering Emulsion Polymerization

摘要

Phase change materials (PCMs) have been widely investigatedfortheir ability to store enormous amounts of heat while maintainingambient temperature during phase transition. In this study, microencapsulationPCMs (MEPCMs) were synthesized using the Pickering emulsion methodto address PCMs' defects, such as severe leakage during phasetransition. In this paper, modified SiO2 nanoparticlesare used as emulsion stabilizers, and a polyurethane (PU) shell preparedfrom biobased soy polyols is used to encapsulate PCM ethyl palmitatefor the successful fabrication of microcapsules. According to thefindings, when the dosage of modified SiO2 nanoparticlesreached 0.5 wt %, the morphologies and mechanical performance of microcapsulesreached their optimal condition. Meanwhile, M-SiO2-dopedmicrocapsules have greater thermal stability than pure ethyl palmitate.Differential scanning calorimetry (DSC) analysis indicates that whenthe core-shell ratio grows, the MEPCMs' heat storagecapacity increases. The latent heat of MEPCMs reached 118.5 J/g asthe core-shell ratio reached 2:1. Additionally, a higher core-shellratio could help alleviate the supercooling phenomenon of microencapsulationPCMs (MEPCMs). Moreover, the MEPCMs' energy storage efficiencycan reach 93.3% after 50 cycles of heat and cold, demonstrating thatthey have excellent cycle stability.

关键词