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.

第一部分：橡胶轮胎是汽车供应链的关键组成部分，作为唯一接触道路的车辆部件，极大地提高了车辆安全性和燃油效率。根据最近的报告，轮胎在环境温度高的地区老化得更快。虽然氧化也被认为在老化现象中起关键作用，但它只发生在轮胎与空气接触的最高表面。由于基质橡胶的氧化和硬化不是轮胎老化的主要原因，因此将重点放在橡胶-填料界面上是合理的，在该界面处填充橡胶的储存和耗散能量都强烈地局部化。界面现象的关键基础成分是与基体橡胶以及相邻填料接合的结合橡胶。然而，结合橡胶在材料性能和耐久性方面的多方面作用仍然没有答案。为了解决这一差距，交联炭黑填充聚丁二烯和二氧化硅填充聚丁二烯系统将被用作合理的模型。将利用模型填充橡胶在实验室烘箱中的热老化来模拟轮胎在使用中的自然老化。 因此，为了了解驾驶条件下橡胶老化的机制，PI的团队将整合实验和计算多尺度，互补的测量/分析，并为未来的运输获得必要的材料设计见解。通过学术界，工业界和国家用户设施的跨领域合作，该项目通过课程开发和指导研究生，加强本科生的研究培训以及当地学校科学博览会的K-12外展活动，进一步促进广泛的参与。PI将与PI研究所的职业中心合作，采取具体举措，改善代表性不足群体的招聘工作。 第二部分：由于基体橡胶的氧化和硬化不是轮胎老化的主要原因，因此，关注橡胶-填料界面是合理的，在该界面处，填充橡胶的储存和耗散能量都强烈地局部化。界面现象的关键基础成分是与基体橡胶以及相邻填料接合的结合橡胶。然而，结合橡胶在材料性能和耐久性方面的多方面作用仍然没有答案。为了解决这一差距，交联炭黑填充聚丁二烯和二氧化硅填充聚丁二烯系统将被用作合理的模型。将利用模型填充橡胶在实验室烘箱中的热老化来模拟轮胎在使用中的自然老化。中子散射/光谱技术与同位素标记将提供深入了解的结构和动力学的结合橡胶埋在基体橡胶。此外，将进行粗粒度的分子动力学模拟，以补充实验结果，并解开实验无法访问的细节。同时，为了模拟驾驶条件下旋转轮胎的老化，将在振荡变形期间进行操作性X射线光子相关光谱测量。实验将提供同时访问的时间和空间分辨的结构和动态的填料网络结构通过绑定橡胶介导的桥梁。这些结果将允许建立微观标准，以非破坏性的方式测量内部橡胶失效的程度。集成的实验-计算方法沿着模型橡胶将促进对老化橡胶的结构-动力学-性能关系的理解，并获得关于橡胶的丰富而复杂的物理和材料设计见解。该奖项反映了NSF的法定使命，并被认为是值得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的支持。

项目成果

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

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