The synthesis and characterisation of some aliphatic hyperbranched polyesters
The attempted syntheses of potential AB(_2) monomers for the production of hyperbranched polyesters has been described. The synthesis of poly(diethyl 3- hydroxyglutarate) has been reported and the characterisation of the products discussed fully. The use of soft ionisation mass spectrometry (MALDI-TOF MS) has been described and the results illustrate the number of different processes occurring during the polyesterification. (^13)C nmr spectroscopy has been shown to be a viable technique in the determination of the degree of branching of these hyperbranched polymers. The synthesis of core terminated hyperbranched polyesters has also been described. It was found that the coupling reactions of the core to the monomer/reactive focus was not efficient, hence only slightly improving the properties of the resulting hyperbranched polymers. The cross-linking of poly(diethyl 3-hydroxyglutarate) was attempted using two cross-linking agents, pentaerythritol tetra-acetate and 1,5-pentanediol, under a variety of conditions. Coupling of esters occurred, but the formation of an insoluble gel was not realised.