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The design of radiolabeled carbon‐14 polymers
Author(s) -
Shemilt Gary,
Newby Mark,
Kitson Sean L.
Publication year - 2007
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.1234
Subject(s) - chemistry , polymer , dispersity , carbon fibers , hexamethylenediamine , molar mass distribution , ethylene oxide , polymer chemistry , organic chemistry , carboxymethyl cellulose , sodium , copolymer , materials science , polyamide , composite number , composite material
This paper outlines three methods for the incorporation of carbon‐14 radiolabels into polymers. The first method discussed used the radiolabeled starting material, [1,6‐ 14 C]hexamethylenediamine 2 . The reaction of 2 with sodium dicyanamide led to a carbon‐14 polybiguanide 3 with a wide molecular weight distribution. An improvement to this reaction was to react 2 with biguanide. This produced 3 with a tighter molecular weight distribution. Modification of side chains in polymers provides a facile route to incorporate carbon‐14 labels. This is illustrated in the formation of [ 14 C]carboxymethyl cellulose 6 which resulted in near perfect molecular weight distribution. Another method to incorporate carbon‐14 into polymers was the reaction between the sodium salt of polyethylene glycols (PEGs) with [U‐ 14 C] ethylene oxide. This resulted in oligomer formation and random labeling in the polymer. This was circumvented by synthesizing carbon‐14 PEG esters from the reaction of carbon‐14 labeled 2‐bromoethyl esters with PEG. This method retained the polydispersity ratio on the reduction of the ester to release the carbon‐14 labeled PEG. Copyright © 2007 John Wiley & Sons, Ltd.