Issue 46, 2023

A fast and efficient way of obtaining the average molecular weight of block copolymers via DOSY

Abstract

Diffusion-ordered NMR spectroscopy (DOSY) allows for solvent-independent molecular weight calibration with low lab variability. Methyl methacrylate standards have been used to calibrate DOSY data for various solvents. Following the Stokes–Einstein equation, a high correlation of the data was obtained when the viscosity of the solvent was taken into account. Moreover, the inter-laboratory and inter-polymer consistency was confirmed by using the pMMA calibration obtained on an NMR system in Germany, which was applied to polystyrene diffusion coefficients that were obtained in Australia. Furthermore, the molecular weight of polymers with added complexity, such as block copolymers, is determined with diffusion data. Butyl acrylate (BA), methyl acrylate (MA), PEG methyl ether acrylate (PEGMEA) and MMA are used as building blocks to synthesize the block copolymers. Firstly, DOSY calibration curves are prepared for the synthesized homopolymers pBA and pPEGMEA. Then, the diffusion data are compared to block copolymers with different compositions of pBA-b-pMA, pBA-b-pPEGMEA and pMMA-b-pPEGMEA and an accurate determination of the molecular weight of the block copolymers could be achieved using the homopolymer calibration curves.

Graphical abstract: A fast and efficient way of obtaining the average molecular weight of block copolymers via DOSY

Supplementary files

Article information

Article type
Paper
Submitted
25 Sept. 2023
Accepted
11 Okt. 2023
First published
23 Okt. 2023

Polym. Chem., 2023,14, 5140-5146

A fast and efficient way of obtaining the average molecular weight of block copolymers via DOSY

P. Voorter, M. Wagner, C. Rosenauer, J. Dai, P. Subramanian, A. McKay, N. R. Cameron, J. J. Michels and T. Junkers, Polym. Chem., 2023, 14, 5140 DOI: 10.1039/D3PY01075A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements