Importance of a reversible reaction for the synthesis of telechelic polymers by means of polycondensation using an excess of one monomer was written by Katoh, Takayoshi;Suzuki, Tomoya;Ohta, Yoshihiro;Yokozawa, Tsutomu. And the article was included in Polymer Chemistry in 2022.Electric Literature of C12H22O4 This article mentions the following:
We show that reversible polycondensation through an alkoxide-catalyzed ester-ester exchange reaction is an effective strategy for the synthesis of telechelic polymers free from contamination with cyclic polymers in the polycondensation of difunctional nucleophilic monomers and difunctional electrophilic monomers. Polycondensation of excess diol formate 1 and 1.0 equivalent of di-Me dicarboxylate 2 at high monomer concentrations afforded polyesters with a hydroxyl group at both ends, uncontaminated with cyclic polymers. On the other hand, the polycondensation of 1.0 equivalent of 1 and excess 2 selectively afforded polymers with a Me ester moiety at both ends, even at lower monomer concentrations Under the same conditions, the irreversible polycondensation of a diol and diacid chloride invariably afforded cyclic polymers, as well as telechelic polymers end-capped with the excess monomer. These results indicated that cyclic polymers, formed during reversible polycondensation, are converted into telechelic polymers by an ester-ester exchange reaction of the cyclic polymers with the excess monomer. Furthermore, the polycondensation of equimolar 1 and 2 in the presence of a sym. ester mol. having two functional groups as an exchange reagent (ExR) afforded a variety of telechelic polyesters with the functional groups derived from the ExR at both ends. Notably, when bis[poly(ethylene glycol) (PEG)] isophthalate was used as the ExR, a PEG-b-polyester-b-PEG triblock copolymer was obtained. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Electric Literature of C12H22O4).
Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Electric Literature of C12H22O4
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics