Telechelic Polymers

Abstract

In this article common synthetic routes toward telechelics, which are polymers with well‐defined functional end groups, are described. Telechelic polymers are available via radical, cationic, and anionic polymerization including reversible addition–fragmentation chain transfer polymerization, atom transfer radical polymerization, and nitroxide mediated polymerization. Furthermore, metathesis has become a valuable tool for the preparation of telechelics. Last but not least selected examples are presented in which step‐growth polymerization has been successfully applied for the synthesis of such well‐defined macromolecules. In specific cases chain scission can also be a useful route.

2‐Mercapto thioxanthone as a chain transfer agent in free‐radical polymerization: A versatile route to incorporate thioxanthone moieties into polymer chain‐ends

“…[7][8][9] As a consequence of the reaction 7 depicted in Scheme 2, thioxanthone moiety should be incorporated into the polymer chain end. Indeed, the UV-vis spectra of the resulting polymethylmethacrylate (PMMA) and polystyrene (PSt) purified by several reprecipitation presents an absorption with a maximum at 380 nm similar to that of the low molecular weight precursor, TX-SH (Figs.…”

Synthesis and Liquid Crystalline Behavior of Random Copolymer of Poly(ethylene oxide) Macromonomer and Liquid Crystalline Monomer by the Photon Transmission Technique

“…A key point is to avoid any reaction of KC 10 H 8 or the active chain end, K-alkoxide, on the functional group fragment of the initiator during alkoxidation and propagation (Scheme 1). In fact, in the course of the preparation of styrene macromonomer, the attack of KC 10 H 8 on styryl group was essentially avoided by very slow (drop-by-drop) addition of the THF solution into a p-vinylphenylalkanol in THF under vigorous magnetic stirring to afford the expected K-alkoxide (2). Then the propagation proceeds normally by ring-opening of EO, since the oxy anion as the propagating species is not reactive enough toward a styryl endgroup as an initiator fragment.…”

“…The areas A of the hysteresis loops for different scan rates were produced and then the data were fitted to the scaling form given in Eq. (2). The scaling behavior of the areas for the random copolymer on a log-log scale is shown in Figure 7.…”

“…Various polymerization techniques including anionic, cationic, radical polymerizations and chemical modifications of polymer ends can be employed in the preparation of macromonomers (1,2). For example, on choosing an initiator containing a polymerizable group, macromonomers can be derived provided this reactive group is totally inert toward the active species generated by its carrier.…”

Phosphorus‐Containing Polysulfones

“…When such groups are bifunctional (e.g. vinyl groups) they can participate in polymerization reactions, yielding graft copolymers or networks; such telechelic polymers are called macromolecular monomers, macromonomers [34,35].…”