(541d) Modeling the Recycling of Polymer Waste

The fundamental issue underlining the difficulty of recycling polymers is that the free energy of polymerization is strongly favorable – thus, reversing this process to create monomers is energetically unfavorable, and hence economically not viable. A metric that characterizes this difficulty is the ceiling temperature,T_ceiling – above T_ceiling depolymerization processes are thermodynamically favorable. Thus, polyethylene with T_ceiling ~ 610⁰C is hard to recycle while polyethyleneterephthalate with T_ceiling~300⁰C is much easier. We shall thus discuss different strategies that can facilitate this key process for families of polymers – in all cases our approach is to combine numerical simulations with back of the envelope calculations to understand experimental results. The ultimate goal is to devise family specific schemes that can bring us closer to the ideal of a circular carbon economy.