NMR of perfluoropolyether diols and their acetal copolymers

Autor:	Emma Barchiesi, Marinella Levi, Stefano Turri
Rok vydání:	1995
Předmět:	Telechelic polymer Polymers and Plastics Organic Chemistry Acetal Carbon-13 NMR Inorganic Chemistry chemistry.chemical_compound End-group chemistry Heteronuclear molecule Polymer chemistry Materials Chemistry Copolymer Molar mass distribution Two-dimensional nuclear magnetic resonance spectroscopy
Zdroj:	Macromolecules. 28:7271-7275
ISSN:	1520-5835 0024-9297
DOI:	10.1021/ma00125a034
Popis:	A 19 F, 1 H, and 13 C NMR structural study is presented for a selected sample of a perfluoropolyether macrodiol (ZDOL), as well as one of its copolymers with formaldehyde. From their 19 F spectra the average composition of perfluorooxymethylene and -oxyethylene units along the chain is clearly evaluated ; the end group analysis allows the calculation of the number average molecular weight and functionality of samples of the macrodiol and, to a first approximation, those of the copolymer. The 1 H and 13 C NMR spectra are studied also in order to clarify the nature of the bridging units in the copolymer between perfluoropolyether segments ; in particular the absence of oligo(oxymethylene) sequences -(OCH 2 ) n - is verified. A comparison is also made with the spectroscopic data of a corresponding low molecular weight compound, which was prepared by reaction of trifluoroethanol with paraformaldehyde. For that reference compound the heteronuclear shift correlation 2D NMR spectrum is also reported and discussed.
Databáze:	OpenAIRE
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