Recycling Poly(Tetrafluoroethylene)

Poly(tetrafluoroethylene) (PTFE) is unique among polymers in its ecological position. Although there has been considerable discussion on recycling waste polymers such as poly(ethylene) (PE), poly(styrene) (PS), and poly(vinyl chloride) (PVC), only poly(tetrafluoroethylene) has been recycled in quantities significant compared to production. Over fifty times more PE is consumed in the form of trash bags for waste disposal than PTFE manufactured. Further, the growth rate of PE, PVC, and PS is continuing at 5–10%o per year while PTFE growth has plateaued. On a tonnage basis, then, the recycling of PTFE appears anomalous. The discrepancy disappears when the economic reward of reprocessing a $2.75/1b material is contrasted with that of a $0.14/1b material. The high scrap value of PTFE provides an incentive for both fabricators and end-users to accumulate waste in reasonably concentrated bulk. Further, freight cost to reprocessing installations is not a significant portion of the polymer cost. Due to the economic incentive a wide variety of methods for up-grading waste PTFE to reprocessable grades have been evaluated. The techniques employed may be transferable to other polymers of greater ecological impact.