NEW POLYMER ARCHITECTURES - RECENT RESULTS WITH POLYROTAXANES

Recent results from our laboratory have shown that the formation of po lyester and polyurethane rotaxanes by polymerization in the presence o f crown ethers is driven by hydrogen bonding of the OH groups with the oxygen atoms of the macrocycles. Here we summarize these findings. Th en we describe the application of this type of self assembly for the p roduction of polyrotaxanes by threading preformed macromolecules and f or the controlled synthesis of branched and crosslinked systems. These latter protocols comprise a new and novel way to prepare mechanically linked, elastomeric materials. Rheological properties of main chain p olyrotaxanes are compared to simple linear backbones; the rotaxanes di splay higher intrinsic viscosities and lower melt viscosities, reflect ing larger hydrodynamic volumes and less entanglement, respectively; t hese are potentially useful aspects in terms of processability of this new class of polymeric materials.