Der Einfluß von Netz- und Hydrophobierungsmitteln auf die Eigenschaften von Zementmörtel

Influence of Wetting and Hydrophobing Agents on the Properties of cement Mortar The relationships between the water requirement of cement mortar, its pore volume and resistence to pressure and water, and the chemical composition of wetting and hydrophobing agents added have been studied. It was found that the rigidity and absorbing capacity are dependent not only upon the density and pore volume of mortar but also upon the chemical structure of the additives. Inspite of reduced density and increased pore volume, it is possible to attain a rigidity of structure and low water absorbence by employing a definite ratio between the hydrophilic and lyophilic ligands in the molecule of the additive.     

Der Einfluß von Antioxidantien auf die Wirkung von UV-Absorbern in verschiedenen Lacksystemen

Influence of Antioxidants on the Action of UV-Absorbers in Various Coating Systems Antioxidants on the basis of amines are undesirable as components of complex UV-absorbers due to their low stability in light. The stability of phenolic antioxidants is largely dependent on the structure of their substituents. Bis-(3,5-ditert.-butyl-4-hydroxy-benzyl)-derivatives of malonic esters, cyanoacetic esters and phosphonoacetic esters possess a good stability in heat and light and they exhibit a certain UV stabilizing action even when used alone. The author investigated the influence of these phenols on the action of UV-absorbers in various coating systems. It could be established in general that although the above phenols improved the action of UV-absorbers, however, they could not even partially substitute the latter without diminishing their action.