Efficient Free-Radical Cyclopolymerization of Oriented Styrenic Difunctional Monomers

Abstract

The synthesis of several difunctional monomers, derived from the introduction of two 4-styrenesubstituted moieties into a covalent skeleton, is described. The more rigid ones, built around malonate moieties and more preorganized to give 3,3′-cyclophane repeating units, failed completely to give soluble, ordered cyclopolymers. The introduction of a certain degree of flexibility in the tethering moiety afforded, by using freeradical initiation, structurally stable cyclopolymers with a high degree of cyclization and good degrees of polymerization. Theoretical calculations detail and strongly support the experimental results. Further chemical elaboration of the obtained cyclopolymeric backbones, by means of the removal of a ketal group, is possible in mild conditions to give systems which can be easily cross-linked thermally, with the loss of H 2 O, at temperatures higher than 100 °C.

Crown Ether Cavity-Containing Copolymers via Controlled Alternating Cyclocopolymerization

“…41 These values indicate clearly that the two types of propagating species preferentially add the other monomer, not the monomer of its own kind. Under the dilute conditions (0.02 M) used in our study, which is lower than the concentration used by others in the cyclopolymerization of difunctional monomers, 3,17 it is even harder for the difunctional styrenic monomers to homopolymerize. Chances of any intramolecular cyclization of the two styrene moieties should be very low.…”

“…1,2 The cyclo(co)polymerization has been considered as one of the most convenient method for the preparation of a polymer with a cyclic structure in the main chain because it provides the unique way to generate cyclic structures in the polymer backbone while making the polymers efficiently. 3,4 Cyclo(co)polymerization generally produces thermodynamically stable five-or six-membered rings as the repeating units along the backbone. 5À9 These very compact rings provide rigidity to the resulting polymers but are too small for the inclusion of other molecules, making them difficult to be used, for example, as stationary phases for chromatographic separation and metal scavengers.…”

Twisting poly(3-substituted thiophene)s: cyclopolymerization of gemini thiophene monomers through catalyst-transfer polycondensation

“…However, with an elaborate monomer design, large macrocycles can be produced, thus resulting in polymeric materials with the capacity of molecular recognition. [3][4][5][6][7][8] In addition, the alternating propagation process can be exploited for sequence control in a polymer main chain. 9,10 As such, cyclopolymerization is an intriguing polymerization methodology that allows access to novel polymer structures.…”

1,2,3‐Triazole‐Incorporated Diacrylate Monomer for Free Radical Cyclopolymerization Through Large Ring Formation

“…[7,8] The recent advance in this field is a monomer deriving from trans-1,2-hexanediol for the formation of cyclopolymers with 19-membered rings. [9] Overall, cyclopolymerization is currently limited by few choices of monomers.…”