Collaborative Research: Localized Frontal Curing-Assisted 3D Printing of Thermosetting Polymers

合作研究：热固性聚合物局部正面固化辅助3D打印

• 批准号: 1933679
• 负责人: Jingjing Qiu
• 金额: $ 9.66万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1933679&HistoricalAwards=false
• 关键词: Collaborative; Research; Localized; Frontal; Curing

This award supports a collaborative research project on a novel 3D printing method for thermosetting polymers, localized frontal curing-assisted 3D printing. Thermosetting polymers are widely used in aircraft, space shuttles, cars, boats, bridges, furniture, and so on. Currently available methods to manufacture thermosetting polymer parts include conventional molding and newly-developed mold-free 3D printing. These methods involve two steps: deposition processing and post-processing curing that are both energy-intensive and time-consuming. In localized frontal curing-assisted 3D printing, deposition and curing are completed simultaneously in a one-step process. An external heat source is used to initialize the curing process and the heat produced by the exothermic curing reaction enables curing to self-propagate through the material as it is deposited. The new method has the potential to impact product design, assembly, and the manufacture of products using thermosetting polymers. As a result it could potentially lead to significant changes and increased competitiveness in many industries of national interest, such as the automotive, aerospace, and marine industries. This project will engage graduate and undergraduate students in the research activities thus preparing them for the advanced manufacturing workforce. Outreach activities based on the research will be used at high school summer camps and for online videos to educate students and the general public about advanced manufacturing. There are four research objectives: (1) to determine effects of curing agent concentration and printing slice size on frontal velocity and front propagation distance; (2) to understand relationships between localized frontal velocity, viscoelastic behavior of thermosetting resins, and geometric fidelity of printed structures; (3) to test the hypothesis that a specific range of frontal velocity will result in higher interlayer bonding strength; and (4) to reveal effects of localized frontal velocity on the mechanical performance of printed structures. To achieve these objectives, the research team will employ both theoretical and experimental approaches. Specifically, effects of curing agent structures and concentration on frontal curing velocity and front propagation distance will be modelled and simulated based on the reaction kinetics and then verified by high-resolution infrared camera. Viscoelastic behavior of thermosetting resins will be studied via real-time rheology characterization and data fitting. Effects of frontal velocity on interlayer bonding strength and mechanical performance of printed structures will be revealed by experimental tests and statistical analysis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持一项关于热固性聚合物的新型3D打印方法的合作研究项目，即局部正面固化辅助3D打印。热固性聚合物广泛应用于飞机、航天飞机、汽车、船只、桥梁、家具等。目前可用的制造热固性聚合物部件的方法包括传统的成型和新开发的无模3D打印。这些方法包括两个步骤：沉积处理和后处理固化，既耗能又耗时。在局部正面固化辅助3D打印中，沉积和固化在一步过程中同时完成。外部热源用于初始化固化过程，放热固化反应产生的热量使固化在沉积时能够通过材料自传播。这种新方法有可能影响产品设计、组装和使用热固性聚合物的产品制造。因此，它可能会导致许多与国家利益相关的行业发生重大变化，并提高竞争力，例如汽车、航空航天和海洋产业。该项目将吸引研究生和本科生参与研究活动，从而为他们成为先进的制造业劳动力做好准备。基于这项研究的外展活动将用于高中夏令营和在线视频，以教育学生和公众有关先进制造的知识。研究目标有四个：(1)确定固化剂浓度和打印片尺寸对前缘速度和前缘传播距离的影响；(2)了解热固性树脂的局部前沿速度、粘弹性行为和打印结构几何保真度之间的关系；(3)验证一定的前缘速度范围会导致层间结合强度增大的假设；(4)揭示局部锋面速度对打印结构力学性能的影响。为了实现这些目标，研究小组将采用理论和实验两种方法。具体而言，固化剂结构和浓度对正面固化速度和正面传播距离的影响将基于反应动力学进行建模和模拟，然后通过高分辨率红外摄像机进行验证。热固性树脂的粘弹性行为将通过实时流变学表征和数据拟合来研究。通过实验测试和统计分析揭示了前缘速度对印刷结构层间结合强度和力学性能的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。