Rubber aging at the microscopic scale

微观尺度的橡胶老化

• 批准号: 2210207
• 负责人: Tadanori Koga
• 金额: $ 39.99万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2210207&HistoricalAwards=false
• 关键词: Rubber; aging; microscopic; scale

PART 1: NON-TECHNICAL SUMMARYRubber tires are a key component of the automotive supply chains and, as the only vehicle part that touches the road, greatly contribute to vehicle safety and fuel efficiency. According to recent reports, tires age faster in regions with high ambient temperatures. While oxidation is also believed to play a critical role in the aging phenomenon, it only occurs at the topmost surface of a tire that is in contact with air. As oxidation and the hardening of a matrix rubber are not primarily responsible for tire aging, it is therefore reasonable to focus on the rubber-filler interface where both storage and dissipation energies of filled rubbers are strongly localized. The key underlying component of the interfacial phenomena is bound rubber that engages with the matrix rubber as well as adjacent fillers. However, the multifaceted role of bound rubber in material properties and durability remains unanswered. To address this gap, cross-linked carbon black filled polybutadiene and silica filled polybutadiene systems will be used as rational models. Artificially aging of model-filled rubbers in a laboratory oven will be utilized to simulate the natural aging of the tire in service. Thus, to understand the mechanism underlying rubber aging under the driving conditions, the PI's group will integrate experimental and computational multiscale, complementary measurements/analysis and derive necessary material design insight for future transportation. Through collaborations across fields in academia, industry, and national user facilities, this project further fosters a wide range of broadening participation through curriculum development and mentoring for graduate students, enhancement of research training of undergraduate students, and K-12 outreach activities at local school science fairs. The PI will embark on specific initiatives aimed at improving the recruitment of underrepresented groups in collaboration with the Career Center at the PI’s institute. PART 2: TECHNICAL SUMMARYAs oxidation and the hardening of a matrix rubber are not primarily responsible for tire aging, it is therefore reasonable to focus on the rubber-filler interface where both storage and dissipation energies of filled rubbers are strongly localized. The key underlying component of the interfacial phenomena is bound rubber that engages with the matrix rubber as well as adjacent fillers. However, the multifaceted role of bound rubber in material properties and durability remains unanswered. To address this gap, cross-linked carbon black filled polybutadiene and silica filled polybutadiene systems will be used as rational models. Artificially aging of model-filled rubbers in a laboratory oven will be utilized to simulate the natural aging of the tire in service. Neutron scattering/spectroscopy techniques with isotope-labeling will provide insight into the structures and dynamics of bound rubber buried in a matrix rubber. In addition, coarse-grained molecular dynamics simulations will be performed to complement the experimental results and unravel the details that are not accessible experimentally. In parallel, to mimic the aging of a rotating tire under a driving condition, in operando X-ray photon correlation spectroscopy measurements during oscillatory deformation will be conducted. The experiments will provide simultaneous access to temporally- and spatially resolved structures and dynamics of a filler network structure via bound rubber–mediated bridges. These results will allow the establishment of the microscopic criteria for measuring the degree of internal rubber failure in a non-destructive manner. The integrated experimental-computational approach along with the model rubbers will advance understanding of the structure-dynamics-property relationship of aged rubbers and derive rich and complex physics and material design insight on rubbers..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.

第1部分：非技术摘要轮胎是汽车供应链的关键组成部分，并且作为触摸道路的唯一车辆部分，对车辆安全和燃油效率做出了巨大贡献。根据最近的报道，在环境温度较高的地区，轮胎年龄更快。虽然氧化也被认为在衰老现象中起着关键作用，但它仅发生在与空气接触的轮胎的最顶部。由于氧化和基质橡胶的硬化并不是轮胎衰老的主要负责，因此，合理地专注于橡胶填充剂界面，在橡胶填充剂界面中，填充橡胶的储存和耗散能量都固定在很强的地方。界面现象的钥匙基础成分是与基质橡胶和相邻填充剂相关的橡胶结合橡胶。但是，绑定橡胶在材料特性和耐用性中的多方面作用仍未得到解答。为了解决这一差距，将交联的碳黑色填充多丁二烯和二氧化硅填充的多丁二烯系统用作有理模型。在实验室烤箱中填充模型橡胶的人为老化将用于模拟轮胎使用的自然老化。为了了解在驾驶条件下橡胶老化的机制，PI组将整合实验和计算多尺度，完整的测量/分析，并得出必要的材料设计洞察力，以实现未来运输。通过学术界，行业和国家用户设施的跨领域的合作，该项目通过课程开发和研究生的心理促进了广泛的参与，对本科生的研究培训的增强以及在当地学校科学博览会上的K-12外展活动。 PI将着手与PI研究所的职业中心合作，旨在改善代表性不足的团体的招聘。第2部分：技术摘要氧化和基质橡胶的硬化并不是轮胎衰老的主要负责，因此，合理地专注于橡胶填充剂界面，在橡胶填充剂界面中，填充橡胶的储存和耗散能量都局部定位。界面现象的钥匙基础成分是与基质橡胶和相邻填充剂相关的橡胶结合橡胶。但是，绑定橡胶在材料特性和耐用性中的多方面作用仍未得到解答。为了解决这一差距，将交联的碳黑色填充多丁二烯和二氧化硅填充的多丁二烯系统用作有理模型。在实验室烤箱中填充模型橡胶的人为老化将用于模拟轮胎使用的自然老化。具有同位素标记的中子散射/光谱技术将提供对基质橡胶内置的结合橡胶的结构和动力学的见解。此外，将进行粗粒细粒的分子动力学模拟，以补充实验结果并揭示无法实验的细节。同时，将在振荡变形过程中模仿驱动条件下旋转轮胎的老化，在Operando X射线光子相关光谱测量中。该实验将通过绑定的橡胶介导的桥梁提供简单地访问填充网络结构的临时和空间分辨结构的访问。这些结果将允许建立微观标准，用于以非破坏性方式测量内部橡胶破坏程度。综合实验计算方法以及模型橡胶将提高人们对老年橡胶的结构 - 动力学生产关系的了解，并在橡胶上得出丰富而复杂的物理和材料设计洞察力。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子功能和广泛的影响来评估Criteria诚实地认为，通过评估诚实的支持。

项目成果

Local conformations and heterogeneities in structures and dynamics of isotactic polypropylene adsorbed onto carbon fiber

• DOI: 10.1016/j.polymer.2022.125584
• 发表时间: 2023-01
• 期刊: Polymer
• 影响因子: 4.6
• 作者: Zhixing Huang;Yashasvi Bajaj;J. Carrillo;Y. Nakanishi;Kiminori Uchida;Kazuki Mita;Takeshi Yamada;T. Miyazaki;B. Sumpter;M. Endoh;T. Koga

Spatial-Temporal Dynamics at the Interface of 3D-Printed Photocurable Thermoset Resin Layers

3D 打印光固化热固性树脂层界面的时空动力学

• DOI: 10.1021/acsaenm.2c00248
• 发表时间: 2023
• 期刊: ACS Applied Engineering Materials
• 作者: Yavitt, Benjamin M.;Wiegart, Lutz;Salatto, Daniel;Huang, Zhixing;Tsapatsaris, Leonidas;Endoh, Maya K.;Poeller, Sascha;Schiel, Manuel;Petrash, Stanislas;Koga, Tadanori
• 通讯作者: Koga, Tadanori