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Critical conditions for liquid chromatography of statistical polyolefins: Evaluation of diene distribution in EPDM terpolymers. Anal Chim Acta 2023; 1246:340856. [PMID: 36764768 DOI: 10.1016/j.aca.2023.340856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023]
Abstract
Liquid chromatography at critical conditions is of interest as it may unravel molecular information on macromolecular structures not accessible by any other analytical techniques. Yet so far, such conditions have never been experimentally established for copolymers, where a particular need for such information exists. Toward this goal, critical conditions for statistical ethylene propylene copolymers were identified. In the first approach the composition of the binary mobile phase was varied at a constant temperature, and secondly by modulating the adsorption-desorption temperature at constant mobile phase composition. Solvents for both methods were identified by using a novel approach that combines structure retention relationships with Hansen Solubility Parameters. As a result, for the first time, the heterogeneity of an ethylene propylene diene terpolymer sample with regard to the pendant double bond of the diene could be determined. The novel chromatographic approach was validated by measuring the composition of fractions taken over the chromatographic run offline by nuclear magnetic resonance. In summary, this work gave the first experimental evidence for the existence of critical conditions for polyolefin random copolymers, as postulated by Brun. This novel chromatographic approach holds immense potential to engineer complex polymers towards future applications by making use of the now-accessible molecular information.
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Arndt JH, Brüll R, Macko T, Garg P, Tacx J. In-depth characterization of polyolefin plastomers/elastomers (ethylene/1-octene copolymers) through hyphenated chromatographic techniques. J Chromatogr A 2020; 1621:461081. [DOI: 10.1016/j.chroma.2020.461081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 10/24/2022]
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Mordan EH, Wade JH, Pearce E, Meunier DM, Bailey RC. A linear mass concentration detector for solvent gradient polymer separations. Analyst 2020; 145:4484-4493. [DOI: 10.1039/c9an02533b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silicon photonic microring resonators are an optical sensor utilized here as a detector for gradient elution liquid chromatography of polymers. Universal refractive index based detection and a linear mass concentration response is observed.
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Affiliation(s)
| | - James H. Wade
- Core R&D Analytical Sciences
- The Dow Chemical Company
- Midland
- Unites States
| | - Eric Pearce
- Core R&D Analytical Sciences
- The Dow Chemical Company
- Midland
- Unites States
| | - David M. Meunier
- Core R&D Analytical Sciences
- The Dow Chemical Company
- Midland
- Unites States
| | - Ryan C. Bailey
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
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Zhou Z, Miller MD, Lee D, Cong R, Klinker C, Huang T, Li Pi Shan C, Winniford B, deGroot AW, Fan L, Karjala T, Beshah K. NMR Study of the Separation Mechanism of Polyethylene–Octene Block Copolymer by HT-LC with Graphite. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01731] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Z. Zhou
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - M. D. Miller
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - D. Lee
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - R. Cong
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - C. Klinker
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - T. Huang
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - C. Li Pi Shan
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - B. Winniford
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - A. W. deGroot
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - L. Fan
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - T. Karjala
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
| | - K. Beshah
- The Dow Chemical Company, 2301 North Brazosport Boulevard, Freeport, Texas 77541, United States
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Macko T, Brüll R, Santonja-Blasco L, Alamo RG. High-Temperature Solvent Gradient Liquid Chromatography of Model Long Chain Branched Polyethylenes. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/masy.201500046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Tibor Macko
- Fraunhofer Institute for Structural Durability and System Reliability (LBF); Division Plastics, Group Material Analytics; Schlossgartenstr. 6 64289 Darmstadt Germany
| | - Robert Brüll
- Fraunhofer Institute for Structural Durability and System Reliability (LBF); Division Plastics, Group Material Analytics; Schlossgartenstr. 6 64289 Darmstadt Germany
| | - Laura Santonja-Blasco
- Department of Chemical and Biomedical Engineering; FAMU/FSU College of Engineering; 2525 Pottsdamer St. Tallahassee FL 32310 USA
| | - Rufina G. Alamo
- Department of Chemical and Biomedical Engineering; FAMU/FSU College of Engineering; 2525 Pottsdamer St. Tallahassee FL 32310 USA
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Lee D, Shan CLP, Meunier DM, Lyons JW, Cong R, deGroot AW. Toward absolute chemical composition distribution measurement of polyolefins by high-temperature liquid chromatography hyphenated with infrared absorbance and light scattering detectors. Anal Chem 2014; 86:8649-56. [PMID: 25117509 DOI: 10.1021/ac501477a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical composition distribution (CCD) is a fundamental metric for representing molecular structures of copolymers in addition to molecular weight distribution (MWD). Solvent gradient interaction chromatography (SGIC) is commonly used to separate copolymers by chemical composition in order to obtain CCD. The separation of polymer in SGIC is, however, not only affected by chemical composition but also by molecular weight and architecture. The ability to measure composition and MW simultaneously after separation would be beneficial for understanding the impact of different factors and deriving true CCD. In this study, comprehensive two-dimensional chromatography (2D) was coupled with infrared absorbance (IR5) and light scattering (LS) detectors for characterization of ethylene-propylene copolymers. Polymers were first separated by SGIC as the first dimension chromatography (D1). The separated fractions were then characterized by the second dimension (D2) size exclusion chromatography (SEC) with IR5 and LS detectors. The concentrations and compositions of the separated fractions were measured online using the IR5 detector. The MWs of the fractions were measured by the ratio of LS to IR5 signals. A metric was derived from online concentration and composition data to represent CCD breadth. The metric was shown to be independent of separation gradients for an "absolute" measurement of CCD breadth. By combining online composition and MW data, the relationship of MW as a function of chemical composition was obtained. This relationship was qualitatively consistent with the results by SEC coupled to IR5, which measures chemical composition as a function of logMW. The simultaneous measurements of composition and MW give the opportunity to study the SGIC separation mechanism and derive chain architectural characteristics of polymer chains.
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Affiliation(s)
- Dean Lee
- The Dow Chemical Company, Analytical Sciences R&D, 1897 Building, Midland, Michigan 48667, United States
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