Four pseudopolyrotaxanes in which aliphatic cyclic oligoesters are threaded onto polystyrene chains were prepared using a statistical approach in which styrene was polymerised in the presence of a high concentration the corresponding cyclic oligomers. The cyclic oligomers were prepared by the cyclo-depolymerisation of aliphatic polyesters. The most heavily loaded pseudopolyrotaxane, poly [styrene-rotaxa(cyclic oligo(hexamethylene sebacate)s] had an M-n 10 100 and an M-w 39.000 and consisted of 41% by weight of cyclics. This corresponds to 25.6 oligomer repeat units per 100 polystyrene repeat units. If the average size of a threaded ring is a trimer, this is equivalent to 8.5 cyclics per 100 polystyrene repeat units and approximately 8 cyclics per polymer chain. DSC analysis indicated that in,the solid state, though the cyclics remained threaded, they were substantially aggregated. (C) 2002 Elsevier Science B.V. All rights reserved.