Journal of Petrochemical Universities
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Preparation and Performance Analysis of Microencapsulated Paraffin with the Polystyrene Shell
Li Fengyan,Hu Rongrong,Xu Yuanhang,Zhao Tianbo
Abstract674)   HTML    PDF (10897KB)(92)      
Phase change material microcapsules (MicroPCMs) with polystyrene as shell material and paraffin as core material were prepared by suspension polymerization. The influence of emulsifying time, the dosages of crosslinking agent (DVB), polymerization times and the mass ratios of core and shell has been studied on the properties of phase change microcapsules, such as chemical compositions, surface morphologies, thermal storage properties and stabilities of the microcapsules were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The results showed that the emulsifying time had no significant influence on the thermal properties of microcapsules. The microcapsule showed better morphology with less wrinkles and less debris when the dosage of divinybenzene(DVB) was 6∶1. The microcapsule prepared with the polymerization time of 3 h had good morphology, relatively uniform size, high latent heat of phase change and high content of core wax. As the mass ratio of the core and wall material increases, the melting temperature of the content of core material (paraffin) increases successively. When the mass ratio of the core and wall material is 3∶1, the latent heat of prepared microcapsule with good thermal stability increases to 125.2 J/g and the content of core material(paraffin) reaches up to 80.9%.
2019, 32 (5): 8-13. DOI: 10.3969/j.issn.1006-396X.2019.05.002
Fabrication and Characterization of Microencapsulated Paraffin with Methyl Methacrylate⁃Based Polymer Shell
Hu Rongrong,Li Fengyan,Zhang Shijie,Zhao Tianbo
Abstract399)   HTML    PDF (2663KB)(207)      
The phase change microcapsules with methyl methacrylate as the shell material and 58# paraffin as the core material were prepared by suspension polymerization. The effects of some factors on the properties of the microcapsules were studied, such as the amounts of emulsifiers and initiators, the mass ratios of the core and shell materials. Chemical compositions, surface morphologies, thermal properties and stabilities of the microcapsules were characterized by Fourier transform infrared (FT⁃IR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The results showed that when the mass fractions of emulsifier PVP and initiator AIBN were 7.0% and 3.9%, respectively, the microcapsules had the best morphology. When the mass ratio of the core and shell material was 3∶1, the microcapsule had a regular spherical shape with a smooth surface. At the same time, the microcapsule with the high enthalpy of phase change had a high heat storage property and stability. The quantity of heat involved in phase transition was 126.97 J/g and the content of paraffin wax as the core material was 85.4%.
2019, 32 (3): 14-19. DOI: 10.3969/j.issn.1006-396X.2019.03.003