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.
Polyurethane (PU) microcapsules containing [BMIm]PF 6 as a lubricant have been fabricated by interfacial polymerization. The stabilizing effect of 10 kinds of emulsifiers towards [BMIm]PF 6 ionic liquid have been delineated. A Pickering emulsion stabilized by lignin showed the best emulsification effect on highly viscous [BMIm]PF 6 . The types and reactivities of monomers have an important influence on the formation of microcapsules. Three kinds of isocyanate (IPDI, MDI, TDI) were reacted with diamines or diols to prepare the PU microcapsules in this work. The optiaml [BMIm]PF 6 @PU microcapsules were obtained when using IPDI and TETA as monomers , under conditions of 5,000 rpm emulsifying rate, 0.5 wt% concentration of lignin Pickering emulsion , and a 3:1 mass ratio of [BMIm]PF 6 /IPDI. The synthesized microcapsules have a regular and compact spherical structure, smooth outer, and inner surfaces with a mean diameter of 43 ± 15 µm, and a thickness of 3.8 µm. The core content of [BMIm]PF 6 @PU microcapsules was determined as >70%, and the initial decomposition temperature was 300 °C. The [BMIm]PF 6 ionic liquid shown excellent lubricating property, ultralow friction coefficient (decreased by 72.7%) and wear rate (decreased by 160 times) were obtained by embedding 30 wt% microcapsules into epoxy compared with pure epoxy.
危险品化学品经营许可证（带存储）