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Synthesis and properties of a novel hyperbranched polyphosphoramidate using an A2 + CB2 approach


Correspondence to: Yuhong Liu, Department of Chemical Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China. E-mail:


The synthesis of hyperbranched polyphosphoramidate (HPPAE) has been successfully achieved via a facial A2 + CB2 approach. First, an AB2 type intermediate is generated by the reaction between the phosphorus chloride group of ethyldichlorophosphate and the secondary amine group of diethanolamine. Second, the above intermediate can further self-condense to produce the hyperbranched polymer. The molecular weight and the structural characterization of HPPAE were checked by gel permeation chromatography and Fourier transform infrared and NMR (13C and 31P) spectroscopy. The degradation study of HPPAE indicated that phosphate and phosphoramide bonds between the branch points are responsible for its complete hydrolysis in an aqueous phosphate buffer (pH 7.4) after 6 days. In addition, HPPAE presents a strong fluorescence peak at 450 nm, exhibiting the potential to track drug transport and distribution in real time. © 2012 Society of Chemical Industry