基于脲醛原位聚合制备聚硫密封剂微胶囊  

Preparation and Characterization of Polysulfide Sealant Microcapsules Based on in situ Polymerization of Urea and Formaldehyde

作　　者：王璇[1] 金涛 王浩伟 廖圣智 杨怀玉[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护实验室,沈阳110016 [2]中国特种飞行器研究所结构腐蚀防护与控制航空科技重点实验室,荆门448035

出　　处：《高等学校化学学报》2018年第2期397-404,共8页Chemical Journal of Chinese Universities

基　　金：国家工信部民机专项项目(批准号:MJ-2014-F-14)资助~~

摘　　要：设计了以脲醛树脂为壁材,聚硫橡胶密封剂为囊芯的微胶囊.在弱酸性条件下,尿素和甲醛在经乳化分散后的聚硫橡胶密封剂微粒表面发生原位聚合,制备了颗粒均匀、形貌规整、分散性好的密封剂微胶囊.通过红外光谱和表面观察技术对微胶囊进行了表征,并且对微胶囊中密封剂含量进行测定.通过对不同物料和反应影响因素(乳化剂浓度、搅拌速度、反应温度和p H值等)进行了系统考察,获得了优化的微胶囊制备工艺条件.为进一步拓展聚硫橡胶密封剂预涂敷技术和工程化应用提供了有益参考.A novel microcapsule of polysulfide sealant was designed and prepared by in situ polymerization technology with poly（urea-formaldehyde）resin（PUF）as shell material and polysulfide rubber as core material under the weak acid conditions.The microencapsulating process of core material,the morphology and chemical structure of microcapsule were monitored and characterized by surface observation and Fourier-transform infrared spectroscopy（FTIR）techniques,respectively.At the earlier stage of emulsification and dispersion,it was found that the particle diameter of dispersed polysulfide rubber decreased nonlinearly with the increase of PVA-124 concentration and PVA-124 was the best emulsifying agent among the various stabilizers studied.Through a large number of experiments,the following optimized conditions for the emulsification and dispersion of polysulfide rubber were obtained：using 1.5%（mass fraction）PVA solution as dispersion phase and Ph Me as diluter,stirring speed 500 r/min and stirring time 0.5 h.At the later stage of polymerization reaction,we found that when the p H of solutions was adjusted to 2.5—3.5 and the reaction temperature was kept at 25℃,the polysulfide rubber microspheres could be gradually coated by PUF with the increase of reaction time,and the polysulfide rubber microspheres were completely encapsuled after the polymerization reaction was continued for 6 h.Then the products were placed in dry oven at 50℃for one day after filtering.The results indicated that PUF microcapsules containing polysulfide rubber could be successfully synthesized,which had regularly spherical shape,rough outer surface and good dispersion.In addition,the optical photos of microcapsules showed that the average particle diameter was about 200μm.Based on the detailed examining of some affecting factors such as emulsifier types and its concentration,stirring speed,reaction temperature and p H value,the optimum prepared condition was obtained.The quantitative analysis results revealed that the encapsulati

关 键 词：聚硫橡胶 脲醛树脂 原位聚合 微胶囊 

分 类 号：O633.12[理学—高分子化学] TQ333-94[理学—化学]