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

该创新-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，适用于替代聚合物改性沥青路面中使用的合成橡胶。美国每年要修建8000万吨沥青路面。S.高交通量需要通过聚合物改性提供弹性。大约400，000，000磅的合成橡胶用于此目的。与此同时，每年产生2.5亿个报废轮胎，富含天然橡胶和合成橡胶。该项目将开发一种工程化的再生轮胎产品，取代沥青中的聚合物，减少能源消耗和温室气体排放。这项技术将通过与生物聚合物复合以使橡胶的密度与沥青相匹配来解决轮胎橡胶改性沥青长期存在的储存稳定性挑战。在建筑、汽车和消费市场，商业机会估计为3亿至10亿美元。该项目将扩大代表性不足的群体的参与，并为分配到该项目的学生提供应用研究，技术转让和创业精神方面的宝贵实践培训。该项目将开发一种颗粒状轮胎橡胶产品，该产品在静态条件下保持在熔融沥青中的储存稳定性，同时提高沥青粘合剂的性能，以满足聚合物改性沥青的规格。现有技术的研磨轮胎橡胶沥青改性中的主要挑战是橡胶颗粒由于密度不匹配而随时间的沉降。该项目的智力价值是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连接起来的基础知识。该项目的关键创新在于认识到轮胎和沥青都是包含极性和非极性域的非均质材料。因此，基于极性和非极性聚合物改性剂两者的磨碎轮胎橡胶（GTR）改性框架可使得聚合物配混技术能够通过调节聚合物配方与任何GTR/沥青粘合剂组合一起起作用。原型改性GTR的储存稳定性将通过传统的环球测试以及新的扫描方法在沥青中进行评估。该技术将建立聚合物添加剂特性如何影响GTR性能的框架，以将其用作沥青改性剂。该奖项反映了NSF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.