Preparation and Characterization of High Content Paraffin Wax Microcapsules and Micro/Nanocapsules with Poly Methyl Methacrylate Shell by Suspension-Like Polymerization

The suspension-like polymerization method is used to obtain poly methyl methacrylate (PMMA)/paraffin wax microcapsules and micro/nanocapsules with high core content. Particle size distribution (PSD) analysis indicates that the average particle size of microcapsules is 94 µm, and the size of micro/nanocapsules ranges in 0.1-19 µm. Differential scanning calorimetry (DSC) and thermalgravimetric analysis (TGA) results show that the fabricated paraffin contents in microcapsules and micro/nanocapsules are as high as 89.5 wt% and 80.2 wt%, respectively with good thermal stability. Thermal cycling tests justify that both the microcapsules and micro/ nanocapsules have good thermal reliability with respect to the changes in their thermal properties after 1000 thermal cycling. This work provides a novel method to prepare microcapsules and micro/nanocapsules with high core content which may benefit further study on thermal energy storage.