Synthesis and characterization of mechanically-linked polymers : determination of the influence of the topological bond

(eng) Macromolecules containing mechanical bonds such as catenanes constitute a class of challenging synthetic targets. Up to now most of the catenane-containing polymers reported previously were poly[2]catenanes obtained by copolymerization of bifunctional catenanes with a comonomer. These materials were only prepared in very small quantities and were characterized by broad molecular weight distributions due to their synthesis by polycondensation. Consequently, very little characterization of their structure or properties was possible. In this study we propose a strategy to couple a [2]catenane to a polymer in order to obtain a defined architecture containing one topological bond in the middle of a polymer (A-cat-A structure). The A-cat-A polymers were obtained by the CuAAc reaction between a propargyle-functionalized catenane and an azide-functionalized polymer. The obtained copolymers were characterized at different levels to probe the influence of the mechanical bond on the polymer. The micellization of the polymers was studied in water and aqueous NaCl. The glass transition was studied by fast-scanning DSC. The influence of the topological bond was studied at the single molecule level by single-molecule atomic force microscopy (AFM-SMFS) and finally, the crystallization behavior was studied by DSC and SAXS/WAXS measurements.