摘要
封闭异氰酸酯由于亲水性较差难以分散于水中,通过亲水改性可以使其具有优异的水分散性,但是较高的解封温度及成本使其难以投入实际应用。对水分散封闭异氰酸酯的研究进展进行综述,并对其应用进行了说明,从实际出发对水分散封闭异氰酸酯的发展趋势做出展望。
The paper intends to provide an overview of the research history and advances of water-dispersible blocked isocyanates （WHI）. The typically blocked isocyanate systems are water-incom- patible and have therefore been prepared in the solvent-borne method. Since the organic solvents have detrimental effects on the en- vironment, there comes the need to develop the alternative techniques likely to be more eco-friendly, one of which is the water-dispersible blocked isocyanates. The typically water-dispersible blocked iso- cyanate systems are made possible by synthesizing the hydrophilic groups of substances into the molecular structure of blocked iso- cyanate, in which water is used directly either as a solvent or as a diluent. The so-called WHI methods are superior in their remarkable water dispersible properties and strong storage stability, for it can get rid of water-isocyanate. The methods can find a wide variety of appli- cations such as in adhesive, water-based baked coating, electro-coat- ing, silk fabric dye additives and paper-pulp enhancing. Two factors may influence the water-dispersible process： a. Structures and types of the hydrophilic agent, such as water dispersible anionic blocked i- socyanate, water dispersible cationic blocked isocyanate, water dis- persible non-ionic blocked isocyanate and water dispersible anionic and cationic blocked isocyanate ; b. The hydrophilie of the blocked a- gent. However, it is required to apply high temperatures to cure and, in some cases, to get rid of the toxic hazards of the blocked agents. Nevertheless, it can be a constraining factor for the uniform curing to be the hydroxyl co-reactants miscibility of the water dispersible blocked isocyanates. The water dispersible properties and storage sta- bility can only be improved by using high-quality materials, but the above-mentioned problems can only be effectively eliminated and the required properties can be achieved by using the isocyanate-blocked process. And, for this purpose, main efforts of the researchers have been centered on gaining better and profounder understanding of the complex mechanism of the WBI as a method and as an approach.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期18-21,共4页
Journal of Safety and Environment
基金
陕西省科技攻关项目(2008K07-32)
陕西省教育厅重点实验室重点科研计划项目(09JS061)
陕西科技大学研究生创新基金项目
关键词
应用化学
水分散封闭异氰酸酯
分散
封闭
applied chemistry
water-dispersible blocked iso- cyanates
dispersible
blocked
