Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610, Perak, Malaysia.
Department of Chemical Engineering, Pakistan Institute of Engineering & Applied Science, Islamabad, Pakistan.
Chemosphere. 2021 Dec;285:131492. doi: 10.1016/j.chemosphere.2021.131492. Epub 2021 Jul 8.
The restoration of mechanical properties is desired for creating the self-healing coatings with no corrosion capabilities. The encapsulation of epoxy resins is limited by various factors in urea and melamine formaldehyde microcapsules. An improved method was developed, where epoxy resin was encapsulated by individual wrapping of poly(melamine-formaldehyde) and poly(urea-formaldehyde) shell around emulsified epoxy droplets via oil-in-water emulsion polymerization method. The synthesized materials were characterized analytically. The curing of the epoxy was achieved by adding the [Ni/Co(2-MI)].2NO as a latent hardener and iron acetylacetonate [Fe(acac)] as a latent accelerator. Isothermal and non-isothermal differential scanning calorimetric analysis revealed lower curing temperature (T = 116 °C) and lower activation energies (Ea ≈ 69-75 kJ/mol). The addition of microcapsules and complexes did not adversely alter the flexural strength and flexural modulus of the epoxy coatings. The adhesion strength of neat coating decreased from 6310.8 ± 31 to 4720.9 ± 60 kPa and percent healing increased from 50.83 to 67.45% in the presence of acetylacetonate complex at 10 wt% of microcapsules.
希望创造具有自我修复能力但无耐腐蚀能力的涂层，以恢复其机械性能。脲醛和蜜胺甲醛微胶囊对环氧树脂的封装受到各种因素的限制。开发了一种改进的方法，通过水包油乳液聚合方法，用聚（蜜胺-甲醛）和聚（脲-甲醛）壳将乳化环氧树脂液滴单独包裹，从而对环氧树脂进行封装。对合成材料进行了分析表征。通过添加[Ni/Co(2-MI)].2NO 作为潜伏性硬化剂和乙酰丙酮铁[Fe(acac)]作为潜伏性促进剂来实现环氧树脂的固化。等温和非等温差示扫描量热法分析表明，较低的固化温度（T=116°C）和较低的活化能（Ea≈69-75 kJ/mol）。微胶囊和配合物的添加并未对环氧树脂涂层的弯曲强度和弯曲模量产生不利影响。在 10wt%微胶囊存在下，乙酰丙酮配合物的加入使涂层的附着力从 6310.8±31kPa 降低到 4720.9±60kPa，修复率从 50.83%提高到 67.45%。
