State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, PR China; Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, PR China.
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, PR China; Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, PR China.
J Hazard Mater. 2015 Aug 15;293:46-53. doi: 10.1016/j.jhazmat.2015.03.037. Epub 2015 Mar 19.
The limitation and regulation of formaldehyde emissions (FE) now shows great importance in wood-based materials such as plywood and particle board manufactured for building and furnishing materials. The widely used formaldehyde-based adhesives are one of the main sources of FE from the wood products. In this work, a new kind of long-term effective formaldehyde scavenger in the microcapsule form was prepared by using an intra-liquid desiccation method. The characterizations of the capsule (UC) were performed including the morphologies, the yields, the loading efficiency as well as its sustained-release of urea in aqueous conditions. The prepared UC could be integrated in urea-formaldehyde resins by simply physical blending, and the mixtures were available to be applied as the adhesives for the manufacture of plywood. The bonding strength (BS) and the FE of the bonded plywood in both short (3h) and long (12 week) period were evaluated in detail. It was found that the FE profile of the plywood behaved following a duple exponential law within 12 week. The addition of UC in the adhesive can effectively depress the FE of the plywood not only in a short period after preparation but also in a long-term period during its practical application. The slow released urea would continuously suppress the emission of toxic formaldehyde in a sustained manner without obviously deteriorating on the BS of the adhesives.
甲醛释放（FE）的限制和规定现在在胶合板和刨花板等用于建筑和家具材料的人造板材中显得尤为重要。广泛使用的基于甲醛的粘合剂是木制品中 FE 的主要来源之一。在这项工作中，采用内相干燥法制备了一种新型的长效微胶囊形式的甲醛清除剂。对胶囊（UC）的特性进行了表征，包括形貌、产率、载药效率以及在水相条件下的尿素持续释放。通过简单的物理混合可以将制备的 UC 整合到脲醛树脂中，并且可以将混合物用作制造胶合板的粘合剂。详细评估了胶合板的胶合强度（BS）和短期（3h）和长期（12 周）内的 FE。结果发现，胶合板的 FE 曲线在 12 周内呈双重指数规律。在粘合剂中添加 UC 不仅可以在制备后的短时间内有效降低胶合板的 FE，而且可以在实际应用的长期内降低 FE。缓慢释放的尿素将以持续的方式不断抑制有毒甲醛的排放，而不会明显降低粘合剂的 BS。
