Development of Micronized Polyurethaneas as a Comprehensive Resin for Green Buiding Materials

More than 10 million tons of polyurethane (PU) foams are manufactured globally each year, and as much as 20% of that production is unsellable scrap. Combining that manufacturing scrap with end-of-life recycling or disposal of PU foam, every year there is a tremendous waste of material that was made with a large investment of energy and still contains some very useful chemical functionality. Mobius Technologies has developed a patent-pending method of using finely ground waste PU foam as a co-binder resin that can replace chemicals used in the manufacture of oriented strand board (OSB). This foam can be post-consumer or post-industrial recycle, and has been called micronized polyurethane, or MPU. Our key innovation is to un-manufacture polyurethane material from foam, and to do this during manufacture of OSB. In an OSB process, MPU can be caused to revert to isocyanates, bind wood strands, and eliminate the need for more energy-intensive and hazardous binder chemicals. Our objective is to remove technological barriers to allow massive amounts of PU scrap to be recycled this way into the large, established, and hungry market for durable building and construction materials. Specifically, we have sought out catalysts that promote the activity of MPU at a significantly lower temperature, which would allow wide commercial acceptance of the new material and process. Our efforts focus on increasing reactivity of MPU, understanding the effect of these catalysts on the process, and testing on a large enough scale to unlock commercial trials at leading OSB manufacturers. The technology will permit manufacturers to reduce the use of chemicals, reduce toxic impacts, reduce the stream of scrap foam to already overwhelmed landfills, and still maintain the cost and quality of their product. The North American OSB market is large and growing. It more than tripled from 1990 to 2005, with 2005 production estimated at 25 billion sq. ft. In Phase I, a list of nine candidate catalysts was identified, and these were tested as additives in remolded MPU plaques under elevated temperature and pressure. Measured internal bond strength identified the additives that produced a significant improvement relative to unmodified MPU. After additional testing to explore concentration and temperature effects for the remaining candidates, a single best candidate material was identified. This catalytic additive increased the strength of remolded MPU by more than 70% at process temperatures of 135°C and more than 200% at process temperatures of 110°C.