R. 0. Jones and P. Ballone

Density functional (DF) calculations have provided a detailed picture of the basic catalytic reaction the ring-opening polymerization of bisphenol-A polycarbonate (BPA-PC). Simple nucleophilic molecules such as lithium phenoxide (LiOPh) react with the carbonate group of the cyclic ring oligomer, leading with low barriers and almost no change in total energy to a chain with a phenyl carbonate at one end and a phenoxide at the other. The alkali atom at the end of the chain can repeat this process, producing a "living polymer". In our report last year we showed that a classical simulation of a model'suggested by the DF calculations showed that polymerization in this case is entropy driven. We have now extended these calculations to multiple active sites (the Li ions in this case) and learned more about the polymerization transition.