TY - JOUR

T1 - SEC analysis of copolymers of different topologies with branched and linear copolyimides with PMMA blocks as a model system

AU - Kashina, A. V.

AU - Meleshko, T. K.

AU - Bezrukova, M. A.

AU - Yakimansky, A. V.

N1 - Funding Information: The work was supported by Russian Science Foundation (project № 20-13-00270 ). Publisher Copyright: © 2020 Elsevier Ltd Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/11/5

Y1 - 2020/11/5

N2 - For grafted copolyimides with variable length and grafting density of polymethylmethacrylate side chains, the molecular masses were determined using three modes of SEC analysis, which differ in the detectors set. The results were compared with the values obtained (i) using 1H NMR spectra, (ii) those calculated by summing the molecular masses of homopolymer linear blocks that make up the copolymer, as well as (iii) with the absolute values of molecular masses determined by sedimentation-diffusion analysis. It is shown that for branched grafted copolyimides the use of only a refractometric detector or its combination with a viscometric detector in the SEC analysis did not allow for obtaining reliable molecular masses. On the contrary, the combination of refractometric and viscometric detectors with a light scattering detector provided for the determination of the molecular masses close to the respective absolute values. It is also shown that for linear block copolymers, unlike branched copolymers, the molecular masses close to the absolute values can be obtained using any of the three modes of SEC analysis. For the first time, a concept of the critical molecular mass of the side chains of grafted copolyimides is introduced as a quantitative criterion that takes into account the total length and also the density of grafting of the side chains.

AB - For grafted copolyimides with variable length and grafting density of polymethylmethacrylate side chains, the molecular masses were determined using three modes of SEC analysis, which differ in the detectors set. The results were compared with the values obtained (i) using 1H NMR spectra, (ii) those calculated by summing the molecular masses of homopolymer linear blocks that make up the copolymer, as well as (iii) with the absolute values of molecular masses determined by sedimentation-diffusion analysis. It is shown that for branched grafted copolyimides the use of only a refractometric detector or its combination with a viscometric detector in the SEC analysis did not allow for obtaining reliable molecular masses. On the contrary, the combination of refractometric and viscometric detectors with a light scattering detector provided for the determination of the molecular masses close to the respective absolute values. It is also shown that for linear block copolymers, unlike branched copolymers, the molecular masses close to the absolute values can be obtained using any of the three modes of SEC analysis. For the first time, a concept of the critical molecular mass of the side chains of grafted copolyimides is introduced as a quantitative criterion that takes into account the total length and also the density of grafting of the side chains.

KW - Copolyimides

KW - Grafted copolymers

KW - NMR

KW - Sedimentation-diffusion analysis

KW - Size-exclusion chromatography

KW - Triple detection

KW - GRAFT-COPOLYMERS

KW - MOLECULAR POLYIMIDE BRUSHES

KW - TRIBLOCK COPOLYMERS

KW - POLY(METHYL METHACRYLATE)

KW - RADICAL POLYMERIZATION

KW - POLY(EPSILON-CAPROLACTONE)

KW - MORPHOLOGY

UR - http://www.scopus.com/inward/record.url?scp=85091201589&partnerID=8YFLogxK

U2 - 10.1016/j.eurpolymj.2020.110031

DO - 10.1016/j.eurpolymj.2020.110031

M3 - Article

AN - SCOPUS:85091201589

VL - 140

JO - European Polymer Journal

JF - European Polymer Journal

SN - 0014-3057

M1 - 110031

ER -