This paper reports the formation and structure of fast setting geopolymers activated by using three sodium silicate solutions with different modules (1.6, 2.0 and 2.4) and a berlinite-type aluminum orthophosphate. By varying the concentration of the aluminum orthophosphate, different Si/Al-ratios were established (6, 3 and 2). Reaction kinetics of binders were determined by isothermal calorimetric measurements at 20 °C. X-ray diffraction analysis as well as nuclear magnetic resonance (NMR) measurements were performed on binders to determine differences in structure by varying the alkalinity of the sodium silicate solutions and the Si/Al-ratio. The calorimetric results indicated that the higher the alkalinity of the sodium silicate solution, the higher the solubility and degree of conversion of the aluminum orthophosphate. The results of X-ray diffraction and Rietveldt analysis, as well as the NMR measurements, confirmed the assumption of the calorimetric experiments that first the aluminum orthophosphate was dissolved and then a polycondensation to an amorphous aluminosilicate network occurred. The different amounts of amorphous phases formed as a function of the alkalinity of the sodium silicate solution, indicate that tetrahydroxoaluminate species were formed during the dissolution of the aluminum orthophosphate, which reduce the pH value. This led to no further dissolution of the aluminum orthophosphate, which remained unreacted.

† Electronic Supplementary Information (ESI) available: Crystal data and details of structure determination and selected bond parameters of 2-5, CCDC 1522462-1522465, Definition of the angle of distortion. Energy profile of Th2Te2 + [Pt((h 2nb)(dppn)]. 31 P{ 1 H} NMR spectrum of [Pt(TeTh)2(dppn)].The oxidative addition reaction of ditellurides R2Te2 [R = n Bu, Ph, Th (2-thienyl, C4H3S)] to [Pt(η 2 -nb)(dppn)] (nb = norbornene, dppn = 1,2-bis(diphenylphosphino)naphthalene) was found to afford [Pt(TeR)2(dppn)] [R = n Bu (1), Ph (2), Th (3)] and [Pt(TeR)(R)(dppn)] [R = Ph (4), Th (5)] as a result of the cleavage of the Te-Te or C-Te bond, respectively. The reactions and the product distributions were monitored by 31 P{ 1 H} NMR spectroscopy. The spectral interpretation was assisted by the high-yield preparation of [Pt(TePh)2(dppn)] (2) and [Pt(TeTh)2(dppn)] (3) by ligand echange reactions from [PtCl2(dppn)], and by the crystal structure determinations and spectral characterizations of 2 and 3. Two series of reactions were carried out both at room temperature and at -80 o C. One involved the addition of the toluene solution of R2Te2 to that of [Pt(η 2 -nb)(dppn)], and the other the addition of [Pt(η 2 -nb)(dppn)] solution to the R2Te2 solution. The oxidative addition of n Bu2Te2 to [Pt(η 2 -nb)(dppn)] yielded solely [Pt(Te n Bu)2(dppn)]. In case of Ph2Te2 and Th2Te2, the reaction of equimolar amounts of ditelluride and [Pt(η 2 -nb)(dppn)] afforded only [Pt(TeR)(R)(dppn)] (R = Ph, Th), but when an excess of R2Te2 was used, the addition of [Pt(η 2 -nb)(dppn)] to the ditelluride resulted in the formation of a mixture of [Pt(TeR)2(dppn)] and [Pt(TeR)(R)(dppn)] with the latter the main component. An excess of R2Te2 and the lowering of the temperature favoured the formation of [Pt(TeR)2(dppn)]. The reaction energetics in toluene was calculated at revPBE GGA DFT / TZVP(f) level of theory. The increase of the electron withdrawing nature of the organic substituent rendered [Pt(TeR)(R)(dppn)] increasingly stable with respect to [Pt(TeR)2(dppn)]. The computation of the energy profiles of the likely pathways of the oxidative addition indicated that concurrent formation of [Pt(TeR)2(dppn)] and [Pt(TeR)(R)(dppn)] (R = Ph, Th) may be more likely than the formation of the latter due to the decomposition of the former. This was verified experimentally by stirring pure [Pt(TeR)2(dppn)] in toluene for a prolonged time at room tempertature. No decomposition was observed.

Research into bio-based epoxy resins has intensified in recent decades. Here, it is of great importance to use raw materials whose use does not compete with food production. In addition, the performance of the newly developed materials should be comparable to that of conventional products. Possible starting materials are lignin degradation products, such as vanillin and syringaldehyde, for which new synthesis routes to the desired products must be found and their properties determined. In this article, the first synthesis of two amine hardeners, starting with vanillin and syringaldehyde, using the Smiles rearrangement reaction is reported. The amine hardeners were mixed with bisphenol A diglycidyl ether, and the curing was compared to isophorone diamine, 4-4′-diaminodiphenyl sulfone, and 4-Aminonbenzylamine by means of differential scanning calorimetry. It was found that the two amines prepared are cold-curing. As TG-MS studies showed, the thermal stability of at least one of the polymers prepared with the potentially bio-based amines is comparable to that of the polymer prepared with isophorone diamine, and similar degradation products are formed during pyrolysis.

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Schimmelpilzbildung und -wachstum treten insbesondere dann auf, wenn an einem Ort eine Feuchtequelle und ein Nährstoffangebot gleichzeitig vorliegen. Rund 41 % der deutschen Bevölkerung war im eigenen Wohnraum schon einmal mit Schimmelbildung konfrontiert. Aufgrund des hohen Sanierungsbedarfs sind am Markt verschiedene Produkte vertreten. Häufig werden pilzwidrige Spachtel-Beschichtungen aufgebracht. Deren Wirkung basiert meist auf der angeblich dauerhaften Alkalität von Zement- und/ oder Kalkbindemitteln, die bekanntlich durch die Reaktion mit Luft-CO2 abgebaut wird. In anderen Produkten kommen Fungizide zum Einsatz. Schimmelschutzfarben wirken nach Herstellerangaben beispielsweise durch chemisch-organische Biozide, hohe Alkalität, Nanosilber oder silberdotiertes Zinkglaspulver. Durch die Verwendung von alternativen Fungiziden soll das Gesundheitsrisiko gesenkt werden. Eine der Ursachen der Schimmelpilzbildung, nämlich die Kondensation an Wärmebrücken, wird dabei häufig außer Acht gelassen. Zielführender wäre es, die Oberflächentemperatur im entsprechenden Bereich durch den Einsatz von Dämmstoffen zu erhöhen und damit der Kondenswasserbildung vorzubeugen. Eine entsprechende Dämmung muss zudem mit einem Spachtel verputzt werden, welcher die Schimmelbildung zusätzlich verhindert. Die zu entwickelnde Spachtelmasse sollte daher zum Schutz der Dämmstoffe und zusätzlich zur Wärmedämmung beitragen. Das Ziel des hier beschriebenen Forschungsprojekts war es, einen Spachtel auf Grundlage von Gips und nicht toxischen Fungiziden zu entwickeln. Diese Metadaten wurden zur Verfügung gestellt von der Literaturdatenbank RSWB®plus