Huang Mengfei, Liu Yuan, Klier John, Schiffman Jessica D
Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States.
Ind Eng Chem Res. 2020 Mar 11;59(10):4542-4548. doi: 10.1021/acs.iecr.9b06618. Epub 2020 Feb 18.
Thermoset coatings have been used extensively to protect and enhance the appearance of substrates for industrial maintenance and architectural applications. Here, we demonstrate that anionic polymerization can be used to first graft hydroxyethyl methacrylate methylene malonate (HEMA-MM) onto a latex particle at ambient conditions, while subsequent ultraviolet (UV) exposure enabled their crosslinking into robust coatings. At room temperature, in the presence of air and water, the polymerization of HEMA-MM was initiated by anionic carboxyl groups present on the MAA latex particles and subsequently grafted onto the surface of particles. The pendent hydroxyethyl methacrylate (HEMA) group enabled UV-curing via free radical polymerization and the formation of a crosslinked network. Systematic investigations were conducted to study the formation and performance of the crosslinked coatings as a function of HEMA-MM incorporation. The incorporation of 10 wt% HEMA-MM into MAA latex yielded crosslinked coatings with decreased swelling, a heightened glass transition temperature (by ~20 °C) and a 2.9-fold improvement in the Young's moduli compared to controls (without HEMA-MM). Here, we demonstrate a facile method that provides a one-step grafting-functionalization approach using functional methylene malonates to produce UV-curable and high-performance coatings at room temperature and under atmospheric environments.
热固性涂料已被广泛用于工业维护和建筑应用中，以保护基材并提升其外观。在此，我们证明了阴离子聚合可用于在环境条件下首先将甲基丙烯酸羟乙酯亚甲基丙二酸酯（HEMA-MM）接枝到乳胶颗粒上，而随后的紫外线（UV）照射可使其交联形成坚固的涂层。在室温下，在空气和水存在的情况下，HEMA-MM的聚合由MAA乳胶颗粒上存在的阴离子羧基引发，随后接枝到颗粒表面。悬垂的甲基丙烯酸羟乙酯（HEMA）基团通过自由基聚合实现紫外线固化并形成交联网络。我们进行了系统研究，以研究交联涂层的形成和性能与HEMA-MM掺入量之间的关系。与对照组（不含HEMA-MM）相比，在MAA乳胶中掺入10 wt%的HEMA-MM可得到交联涂层，其溶胀度降低，玻璃化转变温度升高（约20°C），杨氏模量提高了2.9倍。在此，我们展示了一种简便的方法，该方法提供了一种一步接枝功能化方法，使用功能性亚甲基丙二酸酯在室温及大气环境下制备可紫外线固化的高性能涂层。
