Synthesis of Cyclic Macromolecules

Abstract

The sections in this article are Introduction Synthesis of Cyclic Structures Ring‐Chain Equilibria and Cyclization Ring‐Chain Equilibria in Siloxane Heterocycles Ring‐Chain Equilibria in other Heterocycles Cyclization Reactions in Polyesters or Polyamides End‐to‐End Cyclization Reactions End‐to‐End Cyclization Based on Bimolecular Processes End‐to‐End Cyclization based on Unimolecular Processes Properties of Cyclic Polymers Dilute Solution Properties Size Exclusion Behavior Limiting Viscosity Numbers Thermodynamic and Hydrodynamic Properties Solid State Properties Structures Derived from Cyclic Polymers Eight‐Shaped Polymers Catenanes and Rotaxanes Conclusions

Influence of the Solvent Quality on Ring Polymer Dimensions

“…In the latter case excluded volume interactions are expected to be screened based on Flory’s theorem, and this blend is mainly used in order to explore the entropic ring–linear interactions. To support our results, we provide additional experimental evidence with another sample of well-characterized polystyrene rings, synthesized in a THF/heptane mixture, but having a different molar mass of 13 800 g/mol . The article is organized as follows: in section we present the materials and methods and in section the results and interpretation.…”

“…There are only limited scattering studies of the structure of ring polymers, ,− due to the limited availability of rings, and especially highly pure rings. The differences in the structure between rings and linear chains are associated with the closed topology of the ring polymer.…”

“…Following the above procedure, we obtained an “as pure as currently possible” ring PS sample, coded further as R161. A sample of smaller PS rings with weight-average molar mass 13 800 g/mol was synthesized in a THF/heptane mixture, 12 purified by LCCC, characterized by SEC, and coded as R14. In addition, fully hydrogenous and deuterated linear PS samples were obtained by anionic polymerization with sec -BuLi in benzene and characterized by SEC and off-line light scattering.…”

“…To support our results, we provide additional experimental evidence with another sample of well-characterized polystyrene rings, synthesized in a THF/heptane mixture, but having a different molar mass of 13 800 g/mol. 12 The article is organized as follows: in section II we present the materials and methods and in section III the results and interpretation. The main conclusions are summarized in section IV.…”