Title of article :
Linear aliphatic polyesters having pendant hydroxyl groups were successfully synthesised by polycondensation using scandium triflate as catalyst. A first set of samples was prepared starting with hexane-, octane-, decane-, and dodecanediol and l-malic aci
Author/Authors :
Linear aliphatic polyesters having pendant hydroxyl groups were successfully synthesised by polycondensation using scandium triflate as catalyst. A first set of samples was prepared starting with hexane-، نويسنده , , octane-، نويسنده , , decane-، نويسنده , , and dodecanediol and l-malic aci، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Pages :
7
From page :
228
To page :
234
Abstract :
A convenient, reliable and efficient method for characterizing hydroxyl functional group of hydroxyl containing polymers (synthetic and commercial) is discussed. It involves an in situ derivatization of hydroxyl group with a reactive reagent, 4-fluorophenyl isocyanate, in an NMR tube followed by integration of the unique 19F resonance contributed to the product vs. that of α,α,α-trifluorotoluene as an internal standard in the 19F NMR spectra. The method introduces distinct advantages over many other methods (e.g. titration, etc.). The spectra of the products appear in a manner that an explicit and accurate resolution can be achieved for the products, namely urethane, and spontaneously formed urea (due to the reaction of trace water and isocyanate in excess amount). The reliability of the quantification was examined using a mixture of hydroxyl containing sample with known hydroxyl values including 1-butanol (containing primary hydroxyl) and 2-propanol (containing secondary hydroxyl). Quantification of hydroxyl group was then exercised for a broad range of high molecular weight polymers, including synthetic poly(ε-caprolactones) and polyester diols and commercial PEGs and the resulting data were compared with the standard ASTM method. In contrast to titration technique, this method can be performed quickly (about 15 min), by a small amount of sample (about 20 mg) as well as using routine NMR spectroscopic techniques.
Keywords :
Polyester diol , Hydroxyl value , PEG , 4-Fluorophenyl isocyanate , 19F NMR spectroscopy , Hydroxyl functional group
Journal title :
European Polymer Journal(EPJ)
Serial Year :
2013
Journal title :
European Polymer Journal(EPJ)
Record number :
1229547
Link To Document :
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