Polymer crystallinity and crystallization kinetics via benchtop 1H NMR relaxometry: Revisited method, data analysis, and experiments on common polymers

POLYMER

卷:145

Article

Raentzsch, Volker¹  Haas, Manuel¹  Oezen, Mueruevvet B.¹  Ratzsch, Karl-Friedrich¹  Riazi, Kamran¹  Kauffmann-Weiss, Sandra²  Palacios, Jordana K.^3,4  Mueller, Alejandro J.^3,4,5  Vittorias, Iakovos⁶  Guthausen, Gisela⁷  Wilhelm, Manfred¹ 

[1] Karlsruhe Inst Technol, ITCP, Engesserstr 18, D-76131 Karlsruhe, Germany

[2] Karlsruhe Inst Technol, ITCP, Hennann von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany

[3] Univ Basque Country, UPV EHU, POLYMAT, Paseo Manuel de Lardizabal 3, E-20018 Donostia San Sebastian, Spain

[4] Univ Basque Country, UPV EHU, Polymer Sci & Technol Dept, Fac Chem, Paseo Manuel de Lardizabal 3, E-20018 Donostia San Sebastian, Spain

[5] Basque Fdn Sci, IKERBASQUE, E-48013 Bilbao, Spain

[6] LyondellBasell Basell Polyolefine GmbH, R&D, Polymer Phys & Characterizat, Bruningstr 50, D-65929 Frankfurt, Germany

[7] Karlsruhe Inst Technol, MVM, EBI, Pro2NMR, Adenauerring 20b, D-76131 Karlsruhe, Germany

关键词: Polymer crystallinity;    Crystallization kinetics;    Semi-crystalline polymers;    Low-field NMR;    TD-NMR;    NMR relaxometry;    Molecular dynamics;   

DOI  :  10.1016/j.polymer.2018.04.066

来源: Elsevier

【 摘 要 】

Semi-crystalline polymers play an enormously important role in materials science, engineering, and nature. Two thirds of all synthetic polymers have the ability to crystallize which allows for the extensive use of these materials in a variety of applications as molded parts, films, or fibers. Here, we present a study on the applicability of benchtop H-1 NMR relaxometry to obtain information on the bulk crystallinity and crystallization kinetics of the most relevant synthetic semi-crystalline polymers. In the first part, we investigated the temperature-dependent relaxation behavior and identified T = T-g + 100 K as the minimum relative temperature difference with respect to T-g for which the mobility contrast between crystalline and amorphous protons is sufficient for an unambiguous determination of polymer crystallinity. The obtained bulk crystallinities from H-1 NMR were compared to results from DSC and XRD, and all three methods showed relatively good agreement for all polymers. In the second part, we focused on the determination of the crystallization kinetics, i.e., monitoring of isothermal crystallization, which required a robust design of the pulse sequence, precise temperature calibration, and careful data analysis. We found the combination of a magic sandwich echo (MSE) with a short acquisition time followed by a CarrPurcell-Meiboom-Gill (CPMG) echo train with short pulse timings to be the most suitable for monitoring crystallization. This study demonstrates the application of benchtop 1H NMR relaxometry to investigate the bulk crystallinity and crystallization kinetics of polymers, which can lead to its optimal use as an insitu technique in research, quality control, and processing labs. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free