SBIR Phase I: Surface Modified Ground Tire Rubber for Additives of Asphalt Based Shingles

该小型企业创新研究第一阶段项目涉及对轮胎橡胶（GTR）颗粒进行表面改性，使GTR能够用作屋顶瓦沥青的添加剂，并改善其在铺路中的使用。这种添加剂取代了目前使用的昂贵的全聚合物添加剂，同时利用了其他废弃商品。现有的工艺使GTR降解，消耗过多的能量，成本高，并且如果脱硫发生则降低GTR的弹性。 总之，这使得最终产品不适合用于屋顶瓦，并降低了其在铺路沥青中的性能。这项研究的目的是开发替代目前技术的方法。该建议的智力价值来自于与通过点击化学和原子转移自由基聚合（ATRP）的组合对GTR颗粒进行聚合物表面改性相关的研究，其中聚合物具有相当大的耐温性。预期的成果和优势包括：简化了表面涂覆工艺，减少了GTR颗粒在沥青混合料中的降解，优化了橡胶-沥青混合物的粘弹性，缩短了混合时间，降低了成本和能量，并改善橡胶颗粒在沥青中的分散性和相容性。该项目的商业潜力将来自于低成本、高质量、热稳定性高的沥青添加剂的成功开发。它将基于表面改性的地面轮胎橡胶（GTR），从而能够开发灵活，耐用，高质量的屋顶材料和增强的铺路沥青。 聚合物涂覆的GTR颗粒提供聚合物添加剂的优点，但使用少得多的聚合物。仅商业聚合物已被掺入用于屋顶和路面的沥青混合物中，但成本很高，目前的市场价格为每磅1.50至1.80美元。 相比之下，添加GTR颗粒的成本仅为每磅0.25美元。经计算，用聚合物涂层对GTR颗粒进行表面改性的初始估计成本比材料成本高约30%。通过减少和/或替代目前使用的昂贵聚合物添加剂的量，将表面涂覆的GTR颗粒掺入到屋顶混合物中将生产成本降低高达~20%。前体材料可以低成本商购获得。除了增强的性能和低成本之外，使用GTR颗粒还将提供环境效益，允许再利用通常在垃圾填埋场中处理的轮胎橡胶废物，并大大减少不可再生资源的使用。

This Small Business Innovation Research Phase I project relates to the application of a surface modification to ground tire rubber (GTR) particles, enabling use of GTR as an additive to asphalt for roofing shingles, and improving its use in paving. This additive replaces the costly all-polymer additives currently used, while making use of an otherwise waste commodity. Existing processes degrade the GTR, consume excessive energy, are high-cost, and decrease the elasticity of the GTR if devulcanization occurs. Altogether, this makes the final product unsuitable for use in roofing shingles, and reduces its performance in paving asphalt. The objective of this research is to develop alternative approaches to the current technology. The intellectual merit of this proposal arises from the research related to polymer surface modification of GTR particles via a combination click chemistry and atom transfer radical polymerization (ATRP), with a polymer having considerable temperature resistance. The anticipated results and advantages include: simplification of the surface coating process, reduced degradation of the GTR particles in an asphalt compound, optimization of the viscoelastic properties of the rubber-asphalt mixture, shortening of the mixing period, reduction of the cost and energy, and improved dispersion and compatibility of rubber particles within the asphalt.The broader impact/commercial potential of this project will stem from the successful development of a low cost, high quality, thermally stable asphalt additive with high dispersibility. It will be based on surface modified Ground Tire Rubber (GTR), enabling the development of flexible, durable, high-quality roofing materials, and enhanced paving asphalt. The polymer coated GTR particles provide the advantages of a polymer additive, but using far less polymer. Commercial polymers alone have been incorporated into mixtures of asphalt for roofing and pavement, but at high cost, with current market prices of $1.50 to $1.80 per pound. In contrast, the addition of GTR particles would cost only $0.25 per pound. The initial estimated cost to surface modify the GTR particles with a polymer coating has been calculated to be ~30% above material cost. The incorporation of surface-coated GTR particles into the roofing mixture reduces the production cost up to ~20% by reducing and/or substituting the amount of expensive polymer additives currently used. The precursor materials are commercially available at low cost. Aside from enhanced performance, and low cost, using GTR particles will provide an environmental benefit, allowing reuse of tire rubber waste typically disposed in landfills, and substantially reduces use of a nonrenewable resource.