a Department of Materials Engineering , Federal University of Rio Grande do Norte , Natal , Brazil.
b Department of Mechanical Engineering , Federal University of Rio Grande do Norte , Natal , Brazil.
J Microencapsul. 2019 Jun;36(4):410-419. doi: 10.1080/02652048.2019.1638462. Epub 2019 Jul 5.
Poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) were prepared by polymerisation and the effect of synthesis parameters, such as pH of the solution and agitation rate, on microcapsules size and shell thickness was evaluated. Scanning electron microscopy (SEM) and Fourier transform infra-red spectroscopy (FTIR) were performed. Adjusted pH conditions (pH = 3.5) and agitation rate (1350 RPM) were found using a design of experiments (DOE). SEM results indicated that microcapsule size was directly affected by agitation rate, whereas shell thickness was mostly affected by pH. After obtaining adjusted synthesis conditions, microcapsules presenting mean size of 60 µm and mean shell thickness of 4 µm were embedded in an epoxy matrix for evaluating the self-healing effect. FTIR and SEM analyses in damaged samples suggested that a healing agent was delivered to the crack location.
采用聚合的方法制备了聚脲甲醛（PUF）微胶囊，其中填充了双环戊二烯（DCPD），并评估了溶液 pH 值和搅拌速率等合成参数对微胶囊粒径和壳厚的影响。进行了扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）分析。通过实验设计（DOE）找到了合适的 pH 值条件（pH=3.5）和搅拌速率（1350 RPM）。SEM 结果表明，搅拌速率直接影响微胶囊粒径，而 pH 值主要影响壳厚。在获得调整后的合成条件后，将粒径为 60 µm、壳厚为 4 µm 的微胶囊嵌入环氧树脂基体中，以评估自修复效果。对损伤样品的 FTIR 和 SEM 分析表明，修复剂已被输送到裂缝位置。
