11a: Aramid Copolymers as Reinforcing Compatibilizers for Mixed Plastics Recycling

Municipal solid waste companies in the United States have been shipping their plastic waste overseas in recent decades but are no longer able to due to import restrictions. Mechanical recycling is now the only option to recover the energy and value invested in plastic materials. The high costs of recycling plastic waste are due to the numerous steps necessary to process the materials, including washing, sorting, shredding, melt-mixing, and pelletizing. Materials recovery facilities are unable to sell many of the common plastics such as polypropylene (PP), low-density polyethylene (LDPE) and polystyrene (PS), because of their low demand. Even well sorted polymers that are commonly recycled, such as high-density polyethylene (HDPE) and polyethylene terephthalate (PET), have poor properties and higher costs compared to their virgin polymer counterparts. The recycling industry, therefore, has to charge more money for inferior plastics that result in downcycled materials for lower grade applications. There are currently no low-cost, commercial solutions that upcycle mixed plastics. Mass adoption of recycled polymers into commercial commodity goods requires value to be added to the recycled material. Luna intends to work with all polymers to eventually make a single stream of plastics recyclable. In Phase I, Luna will focus on the development of a compatibilizers to mix an initial set of immiscible, high-volume plastics: PET and PP. The successful combination of these plastics with Luna’s compatibilizer will result in lightweight, high-value and upcycled mixed plastics. Luna will develop a series of compatibilizers derived from inexpensive aramid materials that reinforce the mixed plastics and create a strong, reinforcing interface between PET and PP. Mechanical properties of the blends will be evaluated in house, and Luna will work with our partners at the University of Massachusetts Lowell to scale up the compatibilizers, develop master batch formulations, and demonstrate their technical efficacy. The National Renewable Energy Laboratory will support Luna with a preliminary life cycle analysis that will evaluate feasibility in terms of emissions reductions, energy, and cost compared to virgin and recycled PET and PP. A full-scale life cycle analysis in Phase II will be used to justify the technology’s commercialization potential.