One-Pot Synthesis and Characterization of Hyperbranched Poly(ester-amide)s from Commercially Available Dicarboxylic Acids and Multihydroxyl Secondary Amines YING LIN, 1,2 ZHONGMIN DONG, 1,2 YUESHENG LI 1 1 State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China 2 Graduate School of the Chinese Academy of Sciences, Changchun branch, Changchun 130022, China Received 6 April 2008; accepted 4 May 2008 DOI: 10.1002/pola.22836 Published online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: A convenient and cost-effective strategy for synthesis of hyperbranched poly(ester-amide)s from commercially available dicarboxylic acids (A 2 ) and multihy- droxyl secondary amine (CB 2 ) has been developed. By optimizing the conditions of model reactions, the AB 2 -type intermediates were formed dominantly during the ini- tial reaction stage. Without any purification, the AB 2 intermediate was subjected to thermal polycondensation in the absence of any catalyst to prepare the aliphatic and semiaromatic hyperbranched poly(ester-amide)s bearing multi-hydroxyl end-groups. The FTIR and 1 H NMR spectra indicated that the polymerization proceeded in the proposed way. The DBs of the resulting polymers were confirmed by a combination of inverse-gated decoupling 13 C NMR, and DEPT-135 NMR techniques. The DBs of the hyperbranched poly(ester-amide)s were in the range of 0.44–0.73, depending on the structure of the monomers used. The hyperbranched polymers exhibited moderate molecular weights with relatively broad distributions determined by SEC. All the polymers displayed low inherent viscosity (0.11–0.25 dL/g) due to the branched na- ture. Structural and end-group effects on the thermal properties of the hyper- branched polymers were investigated using DSC. The thermogravimetric analysis revealed that the resulting polymers exhibit reasonable thermal stability. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5077–5092, 2008 Keywords: hyperbranched; modification; polycondensation; polyesters INTRODUCTION Dendrimers and hyperbranched polymers, to- gether classified as dendritic polymers, have attracted considerable and increasing attention in recent years. 1 In contrast to the dendrimers, hyperbranched polymers have irregular branched structures and low degree of branch- ing. 2 However, hyperbranched polymers still inherit the desirable properties similar to den- drimers, such as three-dimensional globular architecture, good solubility, low solution and bulk viscosity, and easy modification because of the abundance of terminal functional groups. Furthermore, they can be prepared conveniently and cost-effectively on a large scale in a one-pot procedure. 3 Therefore, hyperbranched polymers are considered to be alternatives to dendrimers Correspondence to: Y. Li (E-mail: ysli@ciac.jl.cn) Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 46, 5077–5092 (2008) V V C 2008 Wiley Periodicals, Inc. 5077