Cyclodepolymerisation of bisphenol A polysulfone: evidence for self-complementarity in macrocyclic poly(ether sulfones)
Abstract
The engineering thermoplastic generally referred to as ‘bisphenol A polysulfone’ undergoes fluoride-promoted cyclodepolymerisation; high molar mass polymer is thus transformed into a series of macrocyclic oligomers containing up to at least 72 aromatic rings; those containing up to 24 rings have been isolated as pure compounds, and single-crystal X-ray studies of the cyclotrimer and cyclotetramer reveal shape-complementary pairs and chains of macrocyles, respectively.