Development of micronized polyurethane as a comprehensive resin for green building materials and systems

Engineered wood products, such as plywood and oriented strand board (OSB), are a large and growing segment of the building materials market. They are versatile, inexpensive, and fit well within a forest products strategy of tree farms based on rapidly growing, readily replenished crops. However, they require the use of resins with a manufacturing process that has negative environmental impacts. The resins, such as polymeric methyl diphenyl isocyanate (pMDI), require chemicals derived from petroleum products, release a number of greenhouse gases, use large volumes of process water, and require significant energy investment. Mobius Technologies, Inc. has developed and patented a method of using finely ground waste polyurethane foam (referred to here a MPU) as a co-binder resin in the surface layers of OSB. Replacement of pMDI with MPU reduces the environmental impact of pMDI, diverts waste polyurethane from landfills, and reduces processing cost. Use of MPU, however, has so far been limited to partial replacement of pMDI in only the surface layers of OSB due to the time and temperature required to activate the MPU resin in the OSB process. The goal of this SBIR research effort is to extend the use of MPU to both the face layers and the core layer of OSB. This stands to roughly double the amount of standard OSB resin that can be replaced, as well as roughly double the amount of waste polyurethane diverted from landfills. MPU is produced by a chemical-free, mechanical grinding process that requires an energy investment of 2 MJ per kg of MPU. This energy investment is a mere 2 percent of the energy invested in the original production of polyurethane. The Phase I effort will research a specific thermo-chemical process that stands to reduce the time and temperature required to activate the MPU resin. Several candidate reagents will be tested. The tests will be used to down-select and optimize a single reagent. In Phase II, the optimized process will be tested in full OSB production runs. This will explore the overall process economics as well as the performance characteristics of the OSB product. In the commercialization effort, Mobius Technologies will work with commercial OSB producers to replace industry standard resins with the improved product. Replacement of industry standard resins with Mobius’ MPU product has great potential for reduction of water use, embodied energy, and embodied toxic substances, and increase in recycled content.