Shahabudin Nurshafiza, Yahya Rosiyah, Gan Seng Neon
Chemistry Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Polymers (Basel). 2016 Apr 6;8(4):125. doi: 10.3390/polym8040125.
One of the approaches to prolong the service lifespan of polymeric material is the development of self-healing ability by means of embedded microcapsules containing a healing agent. In this work, poly(melamine-urea-formaldehyde) (PMUF) microcapsules containing a palm oil-based alkyd were produced by polymerization of melamine resin, urea and formaldehyde that encapsulated droplets of the suspended alkyd particles. A series of spherical and free-flowing microcapsules were obtained. The chemical properties of core and shell materials were characterized by Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and proton nuclear magnetic resonance spectroscopy (¹H-NMR). Differential scanning calorimetry (DSC) analysis showed a glass transition around -15 °C due to the alkyd, and a melting temperature at around 200 °C due to the shell. Thermogravimetric analysis (TGA) results showed that the core and shell thermally degraded within the temperature range of 200⁻600 °C. Field emission scanning electron microscope (FESEM) examination of the ruptured microcapsule showed smooth inner and rough outer surfaces of the shell. Flexural strength and microhardness (Vickers) of the cured epoxy compound were not affected with the incorporation of 1%⁻3% of the microcapsules. The viability of the healing reactions was demonstrated by blending small amounts of alkyd with epoxy and hardener at different ratios. The blends could readily cure to non-sticky hard solids at room temperature and the reactions could be verified by ATR-FTIR.
延长聚合物材料使用寿命的方法之一是通过嵌入含有愈合剂的微胶囊来开发自愈能力。在这项工作中，通过三聚氰胺树脂、尿素和甲醛的聚合反应制备了含有棕榈油基醇酸树脂的聚（三聚氰胺 - 尿素 - 甲醛）（PMUF）微胶囊，该聚合反应将悬浮的醇酸颗粒液滴包裹起来。获得了一系列球形且自由流动的微胶囊。通过衰减全反射 - 傅里叶变换红外光谱（ATR - FTIR）和质子核磁共振光谱（¹H - NMR）对核材料和壳材料的化学性质进行了表征。差示扫描量热法（DSC）分析表明，由于醇酸树脂，玻璃化转变温度约为 -15°C，由于壳材料，熔点温度约为200°C。热重分析（TGA）结果表明，核材料和壳材料在200⁻600°C的温度范围内发生热降解。场发射扫描电子显微镜（FESEM）对破裂微胶囊的检查显示，壳的内表面光滑，外表面粗糙。加入1%⁻3%的微胶囊对固化环氧化合物的弯曲强度和显微硬度（维氏硬度）没有影响。通过将少量醇酸树脂与环氧树脂和固化剂以不同比例混合，证明了愈合反应的可行性。这些混合物在室温下可以很容易地固化成不粘的硬固体，并且可以通过ATR - FTIR验证反应。
