Multicyclic Poly(ether ester)s by Polycondensation of Oligo(ethylene glycol)s and Trimesoyl Chloride

Abstract

Monodisperse oligo(ethylene glycol)s were polycondensed with trimesoyl chloride using triethylamine as HCl acceptor. Despite nearly quantitative conversions and relatively high concentrations (0.4 mol/L), no gelation occurred with tri-and tetra(ethylene glycol), regardless of the feed ratio. With a feed ratio around 1.5/1.0 multicyclic poly(ether esters)s free of end groups were isolated and characterized by 1 H NMR and MALDI-TOF mass spectrometry. At concentrations of 0.2 or 0.4 mol/L di-, penta-, and hexa(ethylene glycol)s yielded gels. At concentrations g 0.2 mol/L exclusively gels were obtained from various R,ω-dihydroxyalkanes. However, soluble multicycles were obtained from 1,8-dihydroxy-3,6-dithiaoctane and from 1,4-bis(2-hydroxyethoxy)-2butyne. The influence of conformational differences on the cyclization tendency is discussed. The multicycles derived from tri-and tetraethylene glycol showed cryptand properties and dissolved Li-, Na-, K-, and Cs-benzoate in tetrahydrofuran.

Syntheses of amphiphilic biodegradable copolymers of poly(ethyl ethylene phosphate) and poly(3-hydroxybutyrate) for drug delivery

“…Stannous octoate (Sn(Oct) 2 , Sinopharm Chemical Reagent Co., Ltd., China) was purified according to a method described in the literature [18] . Ethylene glycol (Sinopharm Chemical Reagent Co., Ltd., China) was freshly distilled under reduced pressure prior to use.…”

Polycondensation of ‘a − bn’ or ‘a2 + + bn’ Monomers ‐ A Comparison

“…For the 'a 2 þ b 3 ' polycondensation the trifunctional compounds listed in Figure 10 served as 'b 3 ' monomers. [166][167][168][193][194][195][196] Figure 11 summarizes the tetrafunctional monomers used for 'a 2 þ b 4 ' polycondensations. [197][198][199][200] A simplified two-dimensional presentation of a multicyclic polymer is given in Figure 12 as an exemplarily illustration of this new kind of architecture.…”

Synthesis and Characterization of Complex Mixtures Consisting of Cyclic and Linear Polyamides from EthylBis-Ketal Galactarates

“…Based on polystyrene calibration, the chromatogram shows traces of monomer. Such polydipersities were found for products composed of linear polycondensates and large fractions of cycles (58,59). Only 1,8-diamino-p-menthanediamine, 1l, failed to polymerize with bis-ketal diethyl galactarate.…”