Harnessing the Potential of N‐Heterocyclic Carbenes for the Rejuvenation of Group‐Transfer Polymerization of (Meth)Acrylics

Abstract

Neutral but versatile: N‐heterocyclic carbenes are very efficient catalysts for the group‐transfer polymerization of acrylates and methacrylates in both polar and apolar media. These organocatalysts were also used to design all‐(meth)acrylic di‐ and triblock copolymers.

N‐Heterocyclic carbenes for metal‐free polymerization catalysis: an update

“…The first reported example for this employed a strategy based on GTP. The NHC‐based methodology was independently developed by Waymouth, Hedrick and co‐workers as well as Gnanou, Taton and co‐workers . Key to this type of polymerization is the strong nucleophilicity of the NHCs, which enables the formation of hypervalent Si‐based intermediates.…”

“…The room temperature polymerization of methyl methacrylate (MMA) or tert ‐butyl acrylate in the presence of a GTP transfer agent in THF yielded polymer of controlled molecular weight and weight distribution (typically Đ M ≈ 1.2). These characteristics also allowed for the synthesis of blockcopolymers . Later, the range of suitable monomers for this process was extended to cover other acrylates, methacrylonitrile and N , N ‐dimethylacrylamide …”

Stimulus responsive core-shell nanoparticles: synthesis and applications of polymer based aqueous systems

“…44 However since GTP is not based on a free-radical mechanism, 45 it has been limited to methacrylate monomers only. Therefore, despite the recent improvement of the technique, 46 polymer scientists have focused increasingly on the development of Controlled Living Radical Polymerization techniques (CLRP). 47,48 In CLRP the key step is an equilibrium between active species (propagating polymer chain known as macro-radicals) and dormant species (polymer chains) in order to minimize the probability of termination reactions during the polymerization process by decreasing the concentration of active species (radicals).…”

Sustainable Polymers from Biomass‐Derived α‐Methylene‐γ‐Butyrolactones

“…NHC-catalyzed stepgrowth polymerization has been reported as well (168)(169)(170). Polymerization of α,β-unsaturated esters, such as MMA, has also been recently realized through the classic GTP initiated by SKAs (35,144,145), using NHCs as alternative nucleophilic catalysts to activate the acetal initiator (171,172). Using the Arduengo carbenes, 1,3-di-tert-butylimidazolin-2-ylidene (I t Bu) and 1,3-di-mesitylbutyl-imidazolin-2-ylidene (IMes) (173,174) alone, no MMA conversion was observed in either toluene (52) or THF (172).…”