A hyperbranched polyester based on 3,5-dihydroxybenzoic acid was completely modified with dodecanoyl chloride to result in an amphiphilic, globular polymer, which has a polar core and a nonpolar outer sphere with the ability both to incorporate an organic dye and to interact with a nonpolar matrix. A series of blends were prepared using either polypropylene or polyethylene (HDPE) as the matrix. The content of the polyester as disperse phase was varied between 0.05 and 20 wt %. The blends with polyester contents up to 5% were prepared for colorization of polyolefins using the polyester as a dye carrier. The blends with higher polyester contents were prepared in order to investigate the influence of the hyperbranched material on the material properties. The blends exhibited a heterogeneous morphology with very small particle sizes even at high polyester concentrations. The melt rheology measurements resulted in a reduced complex viscosity for both polyolefins when the hyperbranched polyester was added. The observed melt viscosity of the i-PP blends deviated from the linear mixing rule, whereas the HDPE blends followed it. The use of amphiphilic hyperbranched polyesters as dye carriers allowed a homogeneous distribution of an organic dye in a polyolefin matrix with similar dynamic-mechanical behavior of the blends compared to the case of pure polyolefins. The dyed samples exhibited good stability in extraction experiments.

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Polycondensation of 1,2-cyclohexane dicarboxylic anhydride with a calculated molar excess of di-2-propanolamine led to bis(2-hydroxyalkyl)amide based hydroxy-functional hyperbranched polyesteramides in a straightforward manner. Modification reactions of these polymers with lauric esters was conducted in different synthetic approaches. The obtained polymers were characterized by mass spectrometry, using electrospray ionization (ESI) and matrix assisted laser desorption ionization/timeof-flight (MALDI-TOF) techniques, and by size exclusion chromatography in combination with on-line viscosimetry detection (SEC-DV). Comparison of the experimental results with theoretical calculations showed a satisfactory match on molecular weights and polydispersities with fully modified polyesteramides. These values were found to deviate with unmodified and, to a smaller extent, with partially modified polyesteramides. This phenomenon could be attributed to side reactions of the 2-hydroxypropylamide end groups. The lauric ester modified polyesteramides obtained from either consecutive or simultaneous polycondensation and lauric acid esterification were found to be quite similar in structure and molecular weight distribution. This observation underlined the influence of transesterification reactions under the applied conditions.

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