Foamed Propellants

Foamed propellants based on polymer bonded nitramines show high conversion rates due to their porous structure. The properties of the material can be varied in a wide range by using different explosive fillers, energetic binders and porous structures. Foamed propellants with high energy content and variable burning and material characteristics can be formulated. Due to this flexibility, these propellants can be adjusted to manifold applications. The burning characteristics of these porous charges show specific differences compared to standard gun propellants, e.g. the mass conversion rates are essentially above those obtained by combustion of compact materials. In addition, the burning behavior of foamed propellants depending on pressure deviates from that expected by a straightforward use of Vieille's law. This paper presents an overview on investigations carried out in the field of foamed propellants at Fraunhofer ICT concerning thermodynamical calculations, studies on burning behavior and vulnerability.     

Development and Characterization of Antimicrobial Textiles from Chitosan-Based Compounds: Possible Biomaterials Against SARS-CoV-2 Viruses

Journal of Inorganic and Organometallic Polymers and Materials - Novel antiviral cotton fabrics impregnated with different formulations based on Chitosan (CH), citric acid (CA), and Copper (Cu)...     

Physical–chemical,thermal, and functional properties of achira (Canna indica L.) flour and starch from different geographical origin

Achira (Canna indica L.) is a plant native to the Andes in South America, a starchy source, and its cultivation has expanded to different tropical countries, like Brazil. In order to evaluate the potential of this species, starch and flours with different particle size were obtained from Brazilian achira rhizomes. Proximal analyses, size distribution, SEM, swelling power, solubility, DSC, XRD analysis, and FTIR were performed for characterization of these materials. Flours showed high dietary fiber content (16.5–32.2% db) and high concentration of starch in the case of the smaller particle size fraction. Significant differences in protein and starch content, swelling power, solubility, and thermal properties were observed between the Brazilian and the Colombian starch. All the studied materials displayed the B‐type XRD pattern with relative crystallinity of 20.1% for the flour and between 27.0 and 28.0% for the starches. Results showed that the starch and flour produced from achira rhizomes have great technological potential for use as functional ingredient in the food industry.     

Synthese von substituierten γ-Ketosäuren durch alkalische Ringöffnung von 1,1-disubstituierten Cyclopentandionen-(2,5)

Synthesis of Substituted γ-keto-acids via Alkaline Ring Opening of 1,1-Disubstituted Cyclopentane-2,5-diones 1,1-Disubstituted cyclopentane-2,5-diones are smoothly and completely converted by aqueous sodium hydroxide into substituted γ-keto-acids. This reaction is remarkable, because 1-monosubstituted cyclopentane-2,5-diones are not cleaved hydrolytically even under more drastical reaction conditions.