NMR Characterization of Polyethylene Glycol Conjugates for Nanoparticle Functionalization

Abstract

The molecular weight, purity, and functionalization of polyethylene glycols are often characterized by 1H NMR spectroscopy. Oft-forgotten, the typical 1H NMR pulse sequence is not 13C decoupled. Hence, for large polymers, the 13C coupled 1H peaks arising from the repeating units have integrations comparable to that of the 1H of the terminal groups. Ignoring this coupling leads to erroneous assignments. Once correctly assigned, these 13C coupled 1H peaks can be used to determine both the molecular weight of the polymer and the efficacy of conjugation of a terminal moiety more accurately than the uncoupled 1H of the repeating unit.

Poly-3-hydroxybutyrate-co-3-hydroxyvalerate(PHBV)-Polyethylene glycol 20k(PEG20k) as a promising delivery system for PT2399 in the treatment of disc degeneration

“…4 C), wherein a comparison was made with the structural formula of PHBV and our previous discoveries [ 23 ]. This comparison verified the successful transplantation of mPEG20k onto PHBV [ 24 ].

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What’s in My Ink: An Analysis of Commercial Tattoo Ink on the US Market

“…The NMR data are most consistent with a high molecular weight poly­(ethylene glycol) (PEG), where we are only able to observe the backboneCH 2 units due to the low concentration of the chain ends. The reported 1 H NMR stretches for the backboneCH 2 units in PEG are between δ 3.42 and δ 3.82 ppm, with the major peak at δ 3.5–3.6 ppm. , As the molecular weight of PEG increases, the NMR resolution for peaks outside of the major peak decreases. The primary 13 C NMR peak for the backboneCH 2 units in PEG is found at approximately δ 70 ppm.…”

Study on aging behavior of polyethylene glycol under three wavelengths of ultraviolet light irradiation

“…The chemical shifts of the spectrum are attributed: the peak at 1.24 is the end-group proton at the PEG2000 capping, and the strong peak at 3.63 is the methylene proton peak on the main chain. 33 As the hydrogen on the hydroxyl group is more active, it displaces with the deuterium in deuterated chloroform, changing the position of the peak and broadening or even disappearing the peak shape. After irradiation with three UV lights, the structures of the oxidation products are listed in Table 2.…”