Stoichiometric Control over Partial Transesterification of Polyacrylate Homopolymers as Platform for Functional Copolyacrylates

Abstract

Only recently, post‐polymerization modification reactions of unactivated polyacrylates have been emerging as an attractive alternative to utilizing reactive monomers, enabling the synthetic upcycling of these widely applied polymers. Within this contribution, the triazabicyclodecene‐catalyzed transesterification of polyacrylates is reported, including the reaction kinetics and the broad scope for macromolecular design of functional copolyacrylates. More specifically, the transesterification is performed under equilibrium conditions with a set of primary alcohols whereby the reaction kinetics and the obtained conversion as a function of stoichiometric excess of alcohol are evaluated. The results show that the obtained conversion is dependent on the polarity of the solvent and of the alcohol. Through this approach, the transesterification degree can be accurately controlled by stoichiometry, enabling the precise modulation of the macromolecular structure. Finally, the utility of this approach is demonstrated to incorporate functional side chains that are incompatible with radical polymerization, to facilitate Diels–Alder and thiol‐ene reactions, enabling access to a broad range of functional materials from simple polyacrylate homopolymer precursors.

Poly(N-allyl acrylamide) as a Reactive Platform toward Functional Hydrogels

“…Recently, several research groups started exploring the catalytic upcycling of poly­(meth)­acrylates via transesterification and amidation. ,− Our group developed a direct amidation and transesterification protocol for the modification of polyacrylates by the application of catalytic bases. ,, Here, triazabicyclodecene (TBD) enables transesterification and amidation of the polymeric esters with alcohols and amines, respectively, yielding a wide variety of functional polyacrylates and polyacrylamides using PMA as an unactivated base polymer. In addition, this catalytic approach was also applied to poly­(2-alkyl-2-oxazoline)­s comprising 2-methoxycarboxypropyl-2-oxazoline …”

Synthesis of functional polyacrylamide (co)polymers by organocatalyzed post-polymerization modification of non-activated esters

“…Although some research groups have demonstrated the successful transformation of non-activated esters and amines/alcohols, e.g. , poly(meth)acrylates, 30–37 poly(2-oxazoline)s, 38–43 understanding the reaction kinetics and the relationship between the polymer structure and properties of non-activated esters is still of great interest.…”

Functionalization of poly(methyl acrylate) with formate esters and polyester through ester‐ester exchange reaction

“…Reaction of polymers is an efficient strategy to synthesize functional macromolecules, 4 because the synthesis of monomers containing functional group(s) can be tedious, and in addition, the functional group of the monomer may influence the polymerization behavior. 5 There are two main approaches to the introduction of functional groups into polymers by means of polymer reaction: the reaction of a polymer containing a reactive side chain, such as activated ester 6 or azide group, 7 and the reaction of a conventional polymer 8 such as poly(methyl acrylate) (PMA) 5a,9 or poly(methyl methacrylate) (PMMA). 10 The transesterification of polyacrylates with alcohol is promoted by metal catalysts, including metal alkoxides, 9a-d,10a and organocatalysts 11 have also recently been used.…”