PFI-TT: Storage stable, biopolymer-modified, recycled tire rubber asphalt additives for resilient and sustainable asphalt pavements

这项创新技术转化伙伴关系（PFI-TT）项目的更广泛影响/商业潜力是开发一种颗粒状生物聚合物改性产品，适用于取代聚合物改性沥青路面中使用的合成橡胶。在美国，每年大约建造8000万吨沥青路面。高交通量需要聚合物改性提供的弹性。大约有4亿磅合成橡胶用于此目的。与此同时，每年生产2.5亿只报废轮胎，其中含有丰富的天然橡胶和合成橡胶。该项目将开发一种工程化、可回收的轮胎产品，取代沥青中的聚合物，减少能源消耗和温室气体排放。该技术将通过与生物聚合物混合，使橡胶与沥青的密度相匹配，从而解决轮胎橡胶改性沥青长期存在的储存稳定性问题。据估计，建筑、汽车和消费市场的商业机会为3 - 10亿美元。该项目将扩大代表性不足的群体的参与，并向参与该项目的学生提供应用研究、技术转让和创业方面的宝贵实践培训。该项目将开发一种颗粒状地面轮胎橡胶产品，旨在保持熔融沥青在静态条件下的储存稳定性，同时提高沥青粘结剂的性能，以满足聚合物改性沥青的规格。最先进的地面轮胎橡胶沥青改性的主要挑战是由于密度不匹配导致橡胶颗粒随着时间的推移而沉淀。该项目的智力价值在于通过使用聚合物添加剂和加工代表，产生将热固性橡胶与其密度改性联系起来的基础知识。该项目的关键创新是认识到轮胎和沥青都是异质材料，包含极性和非极性域。因此，基于极性和非极性聚合物改性剂的地面轮胎橡胶（GTR）改性框架可以通过调整聚合物配方使聚合物复合技术与任何GTR/沥青粘结剂组合一起工作。将通过传统的环球测试和新的扫描方法来评估原型改性gtr在沥青中的储存稳定性。这项技术将建立聚合物添加剂特性如何影响GTR性能的框架，以及它们作为沥青改性剂的使用。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。

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project is to develop a pelletized biopolymer-modified product suitable for replacing the synthetic rubbers used in polymer modified asphalt pavements. Each year, about 80 million tons of asphalt pavement is constructed in the U. S. Hight traffic volume requires the resiliency provided by polymer modification. Approximately 400,000,000 pounds of synthetic rubbers are used for this purpose. At the same time, 250,000,000 end-of-life tires are generated each year, rich in both natural and synthetic rubbers. This project will develop an engineered, recycled tire product that replaces polymers in asphalt, reducing energy consumption and greenhouse gas emissions. This technology will be achieved by solving a long-standing storage stability challenge in tire rubber-modified asphalts by compounding with biopolymers to match the density of the rubber with the asphalt. The commercial opportunity is estimated to be $0.3 - 1 billion across the construction, automotive, and consumer markets. The project will broaden participation of underrepresented groups and provide valuable practical training in applied research, technology transfer, and entrepreneurship to the students assigned to the project.The project will develop a pelletized ground tire rubber product engineered to maintain storage stability in molten asphalt under quiescent conditions while enhancing the asphalt binder properties to meet polymer modified asphalt specifications. The primary challenge in state-of-the-art ground tire rubber asphalt modification is the settling of rubber particles over time due to the density mismatch. The intellectual merit of this project is to generate foundational knowledge connecting thermoset rubbers to their density modification though the use of polymer additives and processing represents. The key innovation of this project is the recognition that both tires and asphalt are heterogeneous materials that contain both polar and non-polar domains. Accordingly, a ground tire rubber (GTR)-modification framework based upon both polar and non-polar polymer modifiers may enable polymer compounding technology to function with any GTR/asphalt binder combination by adjusting the polymer formulation. Storage stability of prototype modified GTRs will be evaluated in asphalt through both legacy ring-and-ball testing as well as new scanning methods. This technology will establish the framework of how the polymer additive characteristics impact the GTR properties with respect to their use as asphalt modifiers.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.