Neuere Mengenstrommessungen zur Normung von Düsen und Blenden

Ohne Zusammenfassung VDI Mitteilung aus der Betriebskontrolle Oppau der I. G. Farbenindustrie A.-G.     

Ueber Vorkommen und Bestimmung der Milchs?ure im Weine

Ohne Zusammenfassung Mittheilung aus der k. k. allgemeinen Untersuchungsanstalt für Lebensmittel in Wien.     

Recycling of rigid polyurethane foam: Micro-milled powder used as active filler in polyurethane adhesives

Rigid polyurethane (PUR) foams are widely used as heat insulation material in construction industry or for electronic appliances manufacturing. After finishing their life-time, it is necessary to eliminate foam wastes. The aim of this study was to prepare a pair of industrial PUR adhesives of medium viscosity containing recycled rigid PUR foam. Three methods of milling were tested: knife-milling, two-roll milling, and ball-milling. Only two-roll milling gives the PUR micro-powder usable for following adhesives modification. The micro-powder was used as passive filler in PUR adhesives and potential reactivity for polyol pack replacement was studied. Hydroxyl and amine numbers were determined in mixture with virgin polyol. One-component PUR prepolymer adhesive was prepared using various dosages of the micro powder and the tensile strength of bound wood was measured. As additional parameters, also free film adhesive mechanical parameters were tested and particle size distribution of the micro powder was analyzed. Two adhesive formulations were prepared for independent evaluation of the micro powder reactivity. The results showed growing of the mechanical strength of wood bonding with growing dosage of the micro powder.     

Polypyrrole-coated fiber-scaffolds: Concurrent linear actuation and sensing

Conducting polymers such as polypyrrole (PPy) can be deposited on various substrates to obtain conductive electroactive coatings. While electrochemical coatings are generally considered to be more effective, chemical coatings are more industrially suitable, especially on complex substrates. In this work, we aimed to explore the electro-chemo-mechanical response of conductive fiber scaffolds (CFS) prepared by coating PPy (chemically) on glucose-gelatin nanofibre scaffolds. Electroactivity was readily observed in both aqueous and propylene carbonate solutions of lithium bis(trifluoromethanesulfonyl)imide, with mainly anion activity in both cases. A higher actuation response was achieved in the aqueous solutions with strain in the range of 1.2% and stress in the range of 3 kPa. Under both cyclic voltammetry and square wave potential steps driving, stable actuation for over 100 cycles was maintained. In addition to actuation, the CFS samples exhibited concurrent sensory properties, in sensing current densities and mechanical load. The PPy-coated CFS material functioning as both an actuator and a sensor is envisaged to have potential applications in smart materials, soft robotics or e-skin. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48533.