论文部分内容阅读
采用原位聚合法制备以液体石蜡为囊芯、密胺树脂为囊壁的相变微胶囊,考察了乳化工艺、预聚时间、囊壁含量和聚合反应时间对微胶囊质量的影响,优化了制备工艺.利用电子天平、扫描电镜、激光粒度仪、傅里叶红外光谱仪(FT-IR)、热分析仪(DSC和TG/DTA)分别研究了优化工艺下微胶囊的囊芯含量、形貌特征、粒径分布、结构和热性能,并考察了其循环稳定性、抗压性能、抗渗透性.结果表明,微胶囊包覆完整无粘连,表面光洁致密,囊芯含量76%(ψ),囊壁厚度至少可达50~100nm,粒径分布集中在1~5μm,平均为3.32μm.DSC显示有2个吸热峰,起始相变温度分别为4.4和28.6℃,总相变潜热14.9J/g.胶囊耐热温度可达215℃,能承受1.0MPa外压,经300次冷/热循环仍保持良好稳定性,且有很高的抗渗透性.
The in-situ polymerization was used to prepare phase-change microcapsules with liquid paraffin as the core and melamine resin as the wall. The effects of emulsification process, prepolymerization time, wall content and polymerization time on microcapsules quality were optimized and optimized Preparation technology.The microcapsule’s capsule core content, morphology were studied by electronic balance, scanning electron microscope, laser particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), thermal analysis (DSC and TG / DTA) The particle size distribution, the structure and the thermal properties of the microcapsules were investigated.The cyclic stability, compressive strength and permeability of the microcapsules were investigated.The results show that the microcapsules are completely coated with no adhesion, the surface is smooth and compact, the core content is 76% (ψ) , The wall thickness of at least up to 50 ~ 100nm, particle size distribution concentrated in the 1 ~ 5μm, with an average of 3.32μm.DSC showed two endothermic peaks, the initial phase transition temperature was 4.4 and 28.6 ℃, the total phase transition latent heat 14.9J / g. Capsule heat-resistant temperature up to 215 ℃, can withstand 1.0MPa pressure, the 300 cold / heat cycle still maintain good stability, and has a high permeability.