Star polymers synthesized with flexible resorcinarene-derived ATRP initiators.

Two octafunctional resorcinarene-based ATRP initiators were synthesised where the initiating sites were separated from the macrocyclic ring with a short spacer. The spacer was introduced to reduce the steric hindrance at the initiating sites and to increase the number of arms in the resulting star polymers. Higher functionalities of starlike poly(tert-butyl acrylates), PtBA, and poly(methyl methacrylates), PMMA, were obtained, compared to the results by the initiators without a spacer. The kinetics of the polymerisations of tBA and MMA were investigated using various catalysts and solvents. The spacer increased the rate of the polymerisation of bulkier tBA monomer, but had little effect on the polymerisation of MMA. (c) 2007 Elsevier Ltd. All rights reserved.