改性酚醛环氧树脂F-51自修复微胶囊的制备

Preparation of Self-healing Microcapsules Based on Modified Phenolic Epoxy Resin F-51

目的研制一种耐温性好、适用于防腐涂料的自修复微胶囊。方法通过活性稀释剂TMPEG改性具有较好耐温性的酚醛环氧树脂F-51,以原位聚合法,采用非离子表面活性剂复合乳化的方法制备脲醛树脂自修复微胶囊。运用光学显微镜(OM)和扫描电子显微镜(SEM)观察微胶囊的分布状况及轮廓形貌,激光粒度分析仪测定微胶囊的粒径值,引入Gauss拟合研究粒径分布。主要讨论乳化剂的选择、用量、原料比、搅拌转速等条件对微胶囊性能的影响,研究最佳合成工艺;利用OM和SEM观察单个微胶囊的形态,结合光衍射原理判断微胶囊芯壁构成;红外光谱仪(FT-IR)探讨其官能团组成,差示扫描量热仪(DSC)测定微胶囊芯材的反应活性,测试室温条件下微胶囊的贮存效果,并由同步热分析仪(TA)测量微胶囊的热失重情况。结果采用OP-10/JFC复合乳化剂,研制出聚脲甲醛包覆酚醛环氧树脂F-51自修复微胶囊,当用量为芯材质量分数的8.0%,原料比为0.8:1,搅拌速率为1600 r/min时,产率最高达82%,粒径分布相对集中,粒径平均值为107μm。OM中光衍射现象明显,在FT-IR特征曲线出现相应特征吸收峰,微胶囊研磨后可固化反应,室温下贮存100 d,失重率不到3.0%,且在250℃范围内可以保持完整囊-芯结构。结论成功制备了包覆修复剂的微胶囊,微胶囊具备反应活性,贮存稳定性及热稳定性良好,研究成果可为自修复防腐涂料的发展提供参考。

The work aims to prepare a self-healing microcapsule of favorable thermotolerance and applicability to anticorrosive coating. Phenolic epoxy resin F-51 of favorable thermotolerance was modified by reactive diluent TMPEG. Urea-formaldehyde resin microcapsules were prepared through in-situ polymerization and nonionic surfactant composite emulsification. The distribution and the morphology of microcapsules were observed by optical microscope（OM） and scanning electronic microscopy（SEM）. The particle size of the microcapsules was determined by laser particle sizer and its distribution was analyzed by combining with Gauss fitting. The effects of emulsifier selection, dosage, raw material ratio, agitation rate and other factors on the performance of the microcapsules were mainly discussed to study the most appropriate synthesis process. OM and SEM were used to observe shape of individual microcapsule and core-wall composition of the microcapsules was determined by combining with the principle of light diffraction. The functional group composition was characterized by fourier transform infrared（FT-IR） and the reaction activity of core material was determined by differential scanning calorimeter（DSC）. The storage effects of microcapsules were tested in room temperature. The thermal weight loss of microcapsules was analyzed by thermogravimetric analysis（TGA）. The self-healing microcapsules made of phenol-formaldehyde resin F-51 covered by polyurea formaldehyde were developed by using OP-10/JFC complex emulsifier. The results demonstrated that the production rate was up to 82% and particle was in centralized distribution with average particle size of 107 μm（dosage： 8% of core mass fraction, raw material ratio： 0.8：1 and agitation rate： 1600 r/min）. Obvious light diffraction phenomenon was observed in OM. Corresponding characteristic absorption peak appeared in the characteristic curve of FT-IR. After the microcapsules were grinded with curing agent, corresponding curing reaction occurred. The rate of weight loss was less than 3.0% after being stored at room temperature for 100 days, and shell-core structure was kept complete within 250 ℃. Self-healing microcapsules of reactivity, favorable storage stability and thermal stability are successfully prepared, and the research results provide a reference for the development of self-healing anticorrosive coating.