Effect of oligo(ethylene glycol) length on properties of poly(oligoethylene glycol terephthalate)s and their cyclic oligomers

Catalyst-Free Single-Step Solution Polycondensation of Polyesters: Toward High Molar Masses and Control over the Molar Mass Range

“…Furthermore, the limited commercial availability of the cyclic oligomers and their timeconsuming synthesis and purification strongly limit the industrial applicability of ROP for the synthesis of PATs. 1,22,40 Lastly, while there are some reports of obtaining high molar masses with ROP, 41 they are still the exception and none of the methods allow for the control over the molar mass at the same time.…”

“…While control over the molar mass has been claimed by some researchers, it remained impossible to combine this advantage with high-molar-mass polymers. , Moreover, a catalyst is still required for this synthesis method, which introduces several major disadvantages ( vide supra ). Furthermore, the limited commercial availability of the cyclic oligomers and their time-consuming synthesis and purification strongly limit the industrial applicability of ROP for the synthesis of PATs. ,, Lastly, while there are some reports of obtaining high molar masses with ROP, they are still the exception and none of the methods allow for the control over the molar mass at the same time.…”

“…In industry, the workhorse catalysts are often antimony-based (e.g., antimony trioxide), which are hazardous. , Other catalysts have also been investigated and used, such as tin-, zinc-, calcium-, aluminum-, zirconium-, magnesium-, and especially titanium-based catalysts, as well as several organocatalytic systems. Nonetheless, all of them exhibit one or more disadvantages, such as toxicity, discoloration, high cost, low availability, susceptibility to hydrolysis, and/or decreased thermo-oxidative stability of the polymers. ,,,,,,,− Finally, the catalyst system also influences the crystallization rate, making it more difficult to reproducibly study the crystallization behavior of these polymers …”

An efficient cyclodepolymerization route for the chemical recycling of poly(ethylene adipate)

“…[28][29][30][31][32][33][34][35][36][37] The obtained cyclic oligoesters can be used as monomers for ring-opening polymerization (ROP), yielding high molecular weight polyesters that cannot to be synthesized by typical condensation polymerization. [38][39][40][41][42][43][44][45][46] Recently, we developed a cascade polycondensation-coupling ring-opening polymerization (PROP) method, where high molecular weight polyesters with high functional group content can be synthesized via the polymerization of cyclic oligoesters with functional diols, greatly extending the applications of cyclic oligoesters and polyesters. [47][48][49][50][51] Although cyclic monomers can be synthesized by the pseudo-high dilution cyclization (PHDC) of diacyl chlorides with diols, their yields are quite low (20-40%) with large amounts of solvents used.…”

Helical Crystals in Aliphatic Copolyesters: From Chiral Amplification to Mechanical Property Enhancement

“…( d )-Isosorbide (IS), an inexpensive chiral biomass monomer, , was incorporated into poly­(ethylene brassylate) (PEB) as the chiral bias to induce polyester chains constructing a highly ordered helical superstructure during the crystallization process. Due to the low reactivity of IS and the side reactions during the prolonged polymerization process, typical condensation–polymerization (CP) can only afford low number-average molecular weight ( M n , < 15K) IS-containing polyesters with poor mechanical properties. − To overcome this obstacle, a facile cascade polycondensation-coupling ring-opening polymerization (PROP) method − was applied to synthesize chiral poly­(ethylene- co -isosorbide brassylate) (PEIB) copolyesters (Scheme ) with an obtained M n of approximately 38K (Table S1). Achiral PEB homopolymer was prepared via traditional ring-opening polymerization (ROP) as the control sample (Scheme S1).…”