Aromatic carboxylates of the rare earths are known for highly efficient luminescence, thus holding the promise of applicability in optical devices, but may be problematic to apply as such due to their structure, which is polymeric in nature. Therefore, means of conversion into molecular species or eventually polymer embeddings are sought, while at the same time maintaining their advantageous optical features. For these purposes, co‐ligations of rare earth p‐aminobenzoates with bidentate bipyridine and phenanthroline, tridentate terpyridine and polyurethanes, which may also be perceived as polydentate ligands, have been carried out. The materials were characterised with focus on their structure and optical performance. Brightly luminescing composites were obtained from reactions with aromatic and aliphatic diisocyanates. Prolonged UV‐irradiation of the materials proved hexamethylene diisocyanates to be superior with regard to photodegradation. Transparent polyurethane monoliths with emission quantum yields between 40 % and 55 % were eventually prepared from covalent attachement of Tb(p‐aminobenzoate)3 and its bipyridine co‐ligated complexes to a hexamethylene diisocyanate/polyol system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-V) has not been used for demanding technical applications yet due to its limited mechanical properties, particularly its high brittleness. An appropriate route to overcome these limitations is the implementation of plasticizers in the PHB-V matrix via compounding. In this paper the use of different types of fatty acids esters as PHB-V plasticizers were investigated. The study describes how the difference in the fatty acid esters structure (mainly fatty acid hydrocarbon chain length) affects their plasticizing effect and thus the PHB-V ductility performance. The best impact properties of PHB-V compounds were obtained for oleic acid methyl ester, palmitic acid methyl ester or lauric acid ethylene glycol monoester. The increase of notched impact strength from 1.4 (for neat polymer) to 4.0-4.1 kJ/m 2 was observed. At the same time stiffness and strength of the polymer decreased but remain on a level sufficient for technical applications. Additional drawback of PHB-V materials is increasing the brittleness over time. Moreover this study shows that the use of oleic acid ethylene glycol monoester or stearic acid ethylene glycol monoester as plasticizers significantly reduces the increase of the brittleness of PHB-V over time. It is relevant that this drawback of PHB-V materials can be significantly improved by plasticizer addition.

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