Schrifttumsberichte

Ohne Zusammenfassung     

Synthese,Struktur und Eigenschaften von hochtemperaturbeständigen Faserpolymeren

Thermomechanically stable fiberpolymers are formed by aromatic molecule segments. In the course of the synthesis of dicarbonic acid dichlorides and diamines in the solvent dimethyl acetamide acetic acid chloride is formed, which causes chainbreaking. X-ray-structure of poly-m-phenylene-isophthalicamide shows, that the hydrogenbond forming carbonamide groups are vertically arranged to the aromatic planes. With this structure model it is possible to explain thermal and mechanical data of aromatic polyamides.     

Smart Identification Frameworks for Ubiquitous Computing Applications

We present our results of the conceptual design and the implementation of ubiquitous computing applications using smart identification technologies. First, we describe such technologies and their potential application areas, then give an overview of some of the applications we have developed. Based on the experience we have gained from developing these systems, we point out design concepts that we have found useful for structuring and implementing such applications. Building upon these concepts, we have created two frameworks based on Jini (i.e., distributed Java objects) and Web Services to support the development of ubiquitous computing applications that make use of smart identification technology. We describe our prototype frameworks, discuss the underlying concepts and present some lessons learned.     

New Starch Phosphate Carbamides of High Swelling Ability: Synthesis and Characterization

The paper describes the synthesis of starch phosphate carbamides by reacting starch with phosphoric acid and urea. A solid state technique in vacuum at elevated temperatures is used. The degree of substitution of phosphate (DS_P) and carbamide groups (DS_C) can be adjusted by the molar ratio of starch: phosphoric acid: urea, the reaction temperature, and time. The starch derivatives prepared show remarkable swelling if the DS_P ranges between 0.2 and 0.3. With increasing content of urea in the reaction mixture the water‐holding ability is still significantly improved, which is explained by chemically and especially physically introduced urea into the starch polymer. Furthermore, the ratio of amylose: amylopectin of the starch samples influences both the DS values and the physicochemical properties, e.g., swelling power and multivalent metal ion adsorption of the products. The structure of the new polymers was determined by means of FTIR, ¹³C‐ and ³¹P NMR spectroscopy as well as by gel permeation chromatography (GPC).