Preparation and thermal properties of microencapsulated paraffin with polyurea/acrylic resin hybrid shells as phase change energy storage materials

Abstract

Microencapsulated paraffin with polyurea/acrylic resin hybrid shells as phase change energy storage materials was obtained in situ by combining interfacial polymerization and suspension-like polymerization. Glycerin (GC) acts as a cross-linking agent to modify the shells. The morphologies, particle size distributions, thermal storage properties, thermal stabilities and thermal reliabilities of microencapsulated phase change materials (MicroPCMs) were determined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TG). The temperature regulation performance of the foam with MicroPCMs was investigated by an infrared thermal imager. DSC results showed that MicroPCMs with polyurea/butyl methacrylate (PU/BMA) possess an improved heat ability and thermal reliability compared to MicroPCMs with polyurea/methyl methacrylate (PU/MMA). The incorporation of GC to shell-forming composition led to an enhancement in thermal storage capacity of the MicroPCMs. The MicroPCMs with GC-modified PU/BMA hybrid shell has the highest PCMs content by as much as 82.6 mass%. The change in latent heat of MicroPCMs with GC-modified PU/BMA hybrid shell was very small of less than 4 mass% after 500 thermal cycles. The infrared thermography indicated that the PU foam incorporating the MicroPCMs with GC-modified PU/BMA hybrid shell has better temperature-regulated property. In conclusion, the MicroPCMs with PU/BMA hybrid shells, especially with GC-modified PU/BMA hybrid shell, possess a promising prospect applying in energy-conserving building materials and thermal control system of shipping packages.