Morphology of reactive PP/PS blends with hyperbranched polymers

To study the efficiency of different mechanism for reactive compatibilization of polypropylene/polystyrene (PP/PS) blends main chain or terminal functionalized PP and terminal functionalized PS have been synthesized by different methods. While the in-situ block and graft copolymer formation results in finer phase morphologies compared to the corresponding non-reactive blends, the morphology development in the ternary blend system PP/PS + HBP (hyperbranched polymer) is a very complex process. HBP with carboxylic acid endgroups reacts preferably with the reactive sites of the oxazoline functionalized PS (PS-Ox) and locates mainly within the dispersed PS-Ox phase. A bimodal size distribution of the PS-Ox particles within the oxazoline modified PP (PP-Ox) matrix phase is observed with big PS-Ox particles (containing the HBP as dispersed phase) and small PS-Ox particles similar in size like the unimodal distributed particles in the non-reactive PP-Ox/PS-Ox blends. Factors influencing the morphology are discussed.     

Synthesis,structures and luminescence of two new Europium(II) Silicate-Chlorides,Eu2SiO3Cl2 and Eu5SiO4Cl6

Eu₂SiO₃Cl₂ and Eu₅SiO₄Cl₆ were prepared by reaction of EuCl₂ with EuSiO₃ and Eu₂SiO₄, respectively, Sr₂SiO₃Cl₂: Eu²⁺ from mixtures of SrCO₃, Eu₂O₃, SrCl₂ · 6H₂O and SiO₂ under reducing conditions. The crystal structures of Eu₂SiO₃Cl₂ [a = 1118.7(5), c = 952.6(1) pm, tetragonal, I4/m, Z = 8, R = 3.3, R_w = 3.0%] and Eu₅SiO₄Cl₆ [a = 900.4(1), b = 1401.7(2), c = 1112.3(2) pm, β = 103.51(1)°, monoclinic, C2/c, Z = 4, R = 3.6, R_w = 2.6%] were determined from four-circle diffractometer data and compared with related compounds. The luminescence properties were investigated at 300 K and at 4.2 K; all compounds show intense bluish-green photoluminescence. Sr₂SiO₃Cl₂:Eu²⁺ shows thermoluminescence.     

Molekül- und Kristallstruktur von Ytterbium(III)-triaqua-trinitrat,Yb(H2O)3(NO3)3

Molecular and Crystal Structure of Ytterbium(III)-triaqua-trinitrate, Yb(H₂O)₃(NO₃)₃ Yb(H₂O)₃(NO₃)₃ crystallizes from a concentrated solution of Yb₂O₃ in nitric acid in a vacuum desiccator at ambient temperature as colourless single crystals. The crystal structure was determined from single crystal four-circle diffractometer data (R3 , Z = 6, a = 1175.5(1), c = 1117.7(2) pm, V_m = 134.25 cm³/mol, R = 3.0%, R_w = 2.9%). The structure may be viewed at as a heavily compressed packing of [Yb(H₂O)₃(NO₃)₃] molecules. Yb³⁺ is coordinated by three bidentate nitrate ligands and three water molecules so that a tricapped trigonal prism (C.N. 9) of oxygen atoms results as the coordination polyhedron.     

Covalently linked heterofullerene-porphyrin conjugates; new model systems for long-lived intramolecular charge separation

Attaching tetraphenyl porphyrins, with peripheral acetyl or malonate groups, to C₅₉N leads to the first covalently linked heterofullerene-porphyrin conjugates that exhibit long-lived intramolecular charge separation.