相反转界面细乳液聚合法制备石蜡纳胶囊与表征

采用相反转乳化的界面细乳液聚合法制备了以交联聚甲基丙烯酯甲酯为壁材,以石蜡为芯材的纳胶囊。利用光学显微镜、激光粒度分析仪、透射电镜、红外光谱仪、差示扫描量热分析仪等研究了含氟助乳化剂FC-4430、丙烯酸十八酯(SA)及芯材投料量对聚合过程、产品表面形貌、粒径、化学结构、储热性能和包覆率的影响。结果表明,FC-4430对相反转有促进作用,可降低胶囊粒子尺寸且利于包封;SA能提高纳胶囊的包覆率和热稳定性;当FC-4430用量为0.4%,SA用量为2%,m(core)∶m(shell)为2∶1时,纳胶囊的相变潜热为91.7 J/g,包覆率为63.3%,包覆效率为95.0%,胶囊粒子为球形,表面光滑,粒径为0.6~1μm,呈明显的核壳结构,芯材直径为300~500 nm。

Preparation and Characterization of Nanocapsulated Paraffin Wax by Interfacial Miniemulsion Polymerization Based on Phase Inversion Emulsification

Phase change material nanocapsules containing paraffin wax were prepared by interfacial miniemulsion polymerization based on phase inversion emulsification with crosslinking poly (methyl methacrylate) as shell material.The prepared nanocapsules were characterized by optical microscope,laser particle size analyzer,transmission electron microscope (TEM),Fourier transform infrared (FT-IR),differential scanning calorimetry (DSC),etc.The influence of co-emulsifier FC-4430,co-monomer stearyl acrylate (SA),mass ratio of paraffin wax to total monomer on the polymerization,morphology,particle size,chemical structure,thermal storage property and encapsulation ratio was investigated.The results show that co-emulsifier FC-4430 is helpful for phase inversion and encapsulation of paraffin wax;the encapsulation ratio and thermal stability are improved by SA.when the dosage of FC-4430 is 0.4 ％,the dosage of SA is 2 ％ and the mass ratio of paraffin wax to total monomer is 2 ∶ 1,the phase change latent heat reaches 91.7 J/g,the encapsulation ratio is 63.3％,and encapsulation efficiency is 95.0％;the prepared nanocapsules are spherical particles with smooth surface morphology and obvious core-shell structure,the diameter of nanocapsules is 0.6～1 μm,and the diameter of paraffin core is 300～500 nm.