Collaborative Project: GOALI: Acrylic Resins Product and Process Design through Combined Use of Quantum Chemical Calculations and Spectroscopic Methods

合作项目：GOALI：结合使用量子化学计算和光谱方法进行丙烯酸树脂产品和工艺设计

• 批准号: 1160169
• 负责人: Masoud Soroush
• 金额: $ 32.02万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1160169&HistoricalAwards=false
• 关键词: Collaborative; Project; GOALI; Acrylic; Resins

Abstract1160169/1159736Soroush / RappeIntellectual Merit. In our recent successful GOALI work, we have made significant advances in understanding the spontaneous thermal polymerization of acrylates in the absence of any conventional thermal initiators. By combining efficient first-principles quantum-mechanical density functional theory (DFT) calculations with spectroscopic measurements of polymer samples, we have identified conclusively the mechanisms for monomer self-initiation and chain transfer reactions, including the reaction intermediates and transition states. We also calculated rate constants (frequency factors and activation energies) for the reactions in the gas phase.Now, building on these results, we propose to improve experimental control of the thermal spontaneous (without addition of conventional thermal initiators) polymerization of alkyl acrylates through coordinated and collaborative experimental and theoretical/computational research. To deepen our theoretical understanding, calculations will be performed with increasingly realistic solvent models, including multiple explicit solvent molecules in the quantum region and recently-developed van der Waals DFT functionals, to improve intermolecular potential energy surfaces. Concurrently, batch reactor polymerization experiments will be designed on the basis of the computational results and conducted to evaluate the influence of solvent type, monomer and solvent concentrations, and temperature on polymer-chain microstructural characteristics and polymerization rate.The specific goals of this project are: (a) We will develop a computationally efficient method of calculating reliable liquid-phase rate constants for spontaneous thermal acrylate polymerization reactions such as monomer self-initiation, co-initiation by monomer and solvent, and chain transfer. (b) We will design and conduct batch polymerization experiments and, using spectroscopic methods, measure the microstructural characteristics of the produced polymer chains to validate and refine our theoretical predictions. (c) Using the developed computational method and batch polymerization experiments, we will study the structure-reactivity relationship for various solvents and monomers with a ketone functional group. (d) We will use these theoretical and experimental understandings to guide our computational screening and experimental validation of novel thermal initiators (solvents that permit rapid but controllable thermal polymerization of acrylates). Our ultimate goal is to design high-performance acrylic resins and chemically self-regulated polymerization processes for the production of acrylic resins at attractive overall cost.Broader Impacts. The potential impacts of this project are societal (through improved safety), environmental, economic, and in human resource development, among others. Spontaneous thermal polymerization allows for the production of higher quality, environmentally friendlier solvent-borne paints and coatings at lower operating costs. Low molecular weight polymer and oligomer solutions have adequately low viscosity?even at high weight percent solids?thus requiring less solvent to be sprayable and brushable. The reduction or elimination of thermal initiators (e. g. azonitrile or organic peroxides, normally the most expensive component of a resin formula) and the increase of reaction rate both lower the operating costs. The elimination of residual groups due to the thermal initiators in the final product (which adversely affect polymer properties such as resistance to UV radiation) and the use of the quantitative understanding in optimal control of the polymerization reactors improve the resin quality. The PIs and Co-PI will train and mentor two doctoral research assistants as well as six undergraduate (REU) students, who will participate in broad range of research activities from quantum-level computations and supercomputing to laboratory experiments and spectroscopic methods. The project results will be released to the public at conferences and in journal and conference proceedings papers. As in our past research activities, students from under-represented groups will be selected, trained and mentored in this project.

Abstract1160169 / 1159736SSOFORMH / RAPPEINTELLECTUAL FEARIT。在我们最近成功的守门员工作中，我们在没有任何常规的热启动器的情况下，在理解丙烯酸酯的自发热聚合方面取得了重大进展。通过将有效的第一原理结合量子机械密度功能理论（DFT）计算与聚合物样品的光谱测量，我们已经最终确定了单体自行定位和链传递反应的机制，包括反应中间体和过渡状态。我们还计算了气相中反应的速率常数（频率因子和激活能）。现在，基于这些结果，我们建议通过协同和协作实验和理论/计算性研究来改善烷基丙烯酸酯的热自发性（不添加常规热启动器）聚合的实验控制。为了加深我们的理论理解，将使用日益逼真的溶剂模型进行计算，包括量子区域中的多个显式溶剂分子和最近开发的van der waal dft功能，以改善分子间势能表面。同时，将根据计算结果设计批处理反应器聚合实验，并进行评估溶剂类型，单体和溶剂浓度的影响，以及温度对聚合物链微观结构特性和聚合速率的温度。聚合反应，例如单体自我定位，单体和溶剂的共同点以及链转移。 （b）我们将设计和进行批处理聚合实验，并使用光谱方法测量产生的聚合物链的微观结构特征，以验证和完善我们的理论预测。 （c）使用开发的计算方法和批处理聚合实验，我们将研究具有酮功能组的各种溶剂和单体的结构反应关系。 （d）我们将使用这些理论和实验性理解来指导我们对新型热启动器的计算筛选和实验验证（允许丙烯酸酯的快速但可控制的热聚合的溶剂）。我们的最终目标是设计高性能的丙烯酸树脂和化学自我调节的聚合过程，以产生丙烯酸树脂以有吸引力的整体成本。该项目的潜在影响是社会（通过改善的安全性），环境，经济和人力资源开发等。自发的热聚合允许以较低的运营成本生产更高质量，环保的溶剂传播涂料和涂料。低分子量聚合物和低聚物溶液具有足够低的粘度？即使在高重量百分比固体时也需要较低的溶剂才能喷涂和可刷。降低或消除热启动器（例如，苯硝基菌或有机过氧化物，通常是树脂配方中最昂贵的组件），并且反应速率的增加均降低了运营成本。由于最终产物中的热启动器而消除了残留组（这不利影响聚合物特性，例如对紫外线辐射的抗性），并在最佳控制聚合反应器的最佳控制中使用定量理解可以提高树脂质量。 PIS和CO-PI将培训和指导两名博士研究助理以及六名本科生（REU）学生，他们将参加从量子级计算以及超级计算到实验室实验和光谱方法的广泛研究活动。该项目结果将在会议以及期刊和会议论文文件中向公众发布。与过去的研究活动一样，将在该项目中选择，培训和指导来自代表性不足的小组的学生。