This Small Business Innovation Research (SBIR) Phase I project will re-engineer an environmentally troublesome waste material, end of life rubber tires, into value-added, sustainable raw materials for the plastics market. Previous work with composites containing ground tire rubber (GTR), manufactured using ambient or cryogenic processing, has yielded limited success. In this project we will use cryogenically-ground GTR to create extruded recycled polypropylene (r-PP) composites. Our preliminary results indicate that cryogenic GTR has a higher percentage of small particles than commercially-available ambient GTR at the same mesh size. Smaller particles provide more boundaries for impact energy dissipation and larger surface area to interact with the polymer matrix. Using this raw material, and building on knowledge of the differences in surface area and chemistry for the two types of particles, we will successfully demonstrate high-performance composite material samples. A successful outcome of this work will enable improved formulations and processing methods, resulting in superior mechanical performance of composites. This performance will be verified by laboratory tests in Phase I, leading to a Phase II effort focused on scale-up and commercialization of this process in conjunction with strategic partners. The broader impact/commercial potential of this project will be to enable the use of recycled rubber powders derived from end of life tires in a value-added product for the plastics market. This will increase the market potential and profitability of this recycling process and expand the range of available options for dealing with the significant environmental issue of approximately 300 million used tires generated per year nationwide. The commercial opportunity is estimated to be $0.3 - 1 billion and is spread across the construction, automotive and consumer markets. Clear and significant societal benefits would also result from the transformation of a problematic environmental waste into a versatile and sustainable raw material
