Inter-American Materials Collaboration: Designing Acrylic Coatings Using Mechanistic Modeling

这一美洲材料合作研究项目由西北大学的琳达·布罗德贝尔特和加拿大女王大学的罗宾·哈钦森共同开展。这项研究的长期目标是通过加深对自由基聚合动力学的理解并在基于建模的工具中获取这些知识来改进工业聚合过程，并为新的聚合材料的设计做出贡献。涂料工业用溶剂型丙烯酸树脂的生产已被选为努力的重点。丙烯酸树脂是许多涂料的基础聚合物，现在生产的溶剂水平比以前更低，生产温度更高。人们对高温二次反应知之甚少，高温二次反应在控制速度和分子结构方面发挥着重要作用，而这些结构又决定了所产生的聚合物的最终用途和产品价值。这项研究提供了一种方法来估计将该模型应用于广泛的聚合体系所需的动力学参数，在这些聚合体系中，完整的速率系数可能尚未通过实验确定。为此，该项目采用了一种合作的三管齐下的方法，需要女王大学和西北大学两个小组的专业知识。首先，将对在严格控制的条件下合成的聚丙烯酸丁酯的结构进行详细的检查(女王大学)。这些结果与数学模型相结合，以完善机理途径并量化这些二次反应的动力学(皇后大学和西北大学)。其次，构建了适用于高温合成自由基共聚物的通用模型(皇后大学和西北大学)，并以实验室规模的实验数据(皇后大学)对苯乙烯/丙烯酸酯/甲基丙烯酸酯三元共聚物进行了检验。最后，将分子模拟作为相对速率系数的先验预测工具(西北大学)。拟议的研究对工业配方和涂料生产的潜在影响很大。如果这项工作取得成功，将提供如何填充用于丙烯酸涂料的一系列潜在单体的速率系数数据库的方法。涂层是汽车行业和其他行业的主要成本，任何可以降低成本或提高性能的进步都会产生影响。拟议的国际合作的教育价值也很高。参与这项工作的研究生接触到一系列涉及聚合物合成和表征的实验技术，精通关键数据分析和基本模型的开发和应用，以解释实验数据和改进制造工艺，并在计算化学工具的应用方面发展专业知识。通过与加拿大研究人员的合作，学生们与包括工业科学家在内的聚合领域的国际专家进行互动，并提高沟通技能。该奖项由材料研究司、化学和运输系统司、国际科学和工程办公室以及数学和物理科学局的多学科活动办公室提供支助。

This Inter-American Materials Collaboration research project is carried out by Linda Broadbelt, Northwestern University, and Robin Hutchinson, Queen's University, Canada. The long-term objective of this research is to improve industrial polymerization processes and to contribute to the design of new polymeric materials by developing a deeper understanding of free-radical polymerization kinetics and capturing that knowledge in modeling-based tools. The production of solvent-borne acrylic resins for the coatings industry has been chosen as a focal point for the effort. Acrylic resins, the base polymer for many coatings, are now produced with lower solvent levels and at higher temperatures than before. Little is known about the high-temperature secondary reactions that play an important role in controlling rate and molecular structure, which in turn determines the end-use properties and product value of the polymers produced. This research provides a methodology to estimate the kinetic parameters required to apply the model to a broad range of polymerization systems where the complete set of rate coefficients may not have been determined experimentally. To this end, this project uses a collaborative, three-pronged approach requiring the expertise of both groups at Queen's and Northwestern Universities. First, a detailed examination of poly(butyl acrylate) structure, synthesized under carefully controlled conditions, will be carried out (Queen's University). These results are combined with mathematical modeling to refine the mechanistic pathway and quantify the kinetics of these secondary reactions (Queen's University and Northwestern University). Second, a general model applicable for high-temperature synthesis of free-radical copolymers is constructed (Queen's University and Northwestern University) and tested against lab scale experimental data (Queen's University) for a styrene/acrylate/methacrylate terpolymer. Finally, molecular modeling is examined as a tool for the a priori prediction of relative rate coefficients (Northwestern University).The potential impact of the proposed research on industrial formulation and production of coatings is high. This work, if successful, will provide the methodology of how to populate databases of rate coefficients for a suite of potential monomers used in acrylic coatings. Coatings are a major cost in the automotive sector and other industries, and any advancement that can reduce costs or improve performance has an impact. The education value of the proposed international collaboration is also high. The graduate students involved in this work are exposed to a wide range of experimental techniques involving polymer synthesis and characterization, become proficient in critical data analysis and in the development and application of fundamental models to interpret experimental data and to improve manufacturing processes, and develop expertise in the application of computational chemistry tools. Through the collaboration with investigators in Canada, students interact with international experts in polymerization, including industrial scientists, and develop improved communication skills. This award is supported by the Division of Materials Research, the Division of Chemical and Transport Systems, the Office of International Science and Engineering, and the Office of Multidisciplinary Activities in the Directorate for Mathematical and Physical Sciences.