Mechanische Eigenschaften von Polyesterfasern bei kurzzeitiger Zugbeanspruchung, 1. Aufbau eines Meßplatzes für schnelle Zugbeanspruchung

The stress-strain behaviour of filament yarns has been determined by variation of strain rates from 10^?1 up to 10⁵%/s. Strain rates up to 10%/s are obtained with a tensile testing machine. The higher strain rates up to 10⁵%/s are obtained with an apparatus using a falling weight by variation of the height of fall and the length of the yarn. Because of the high-speed impact and time of strain/influence down to 10^?4 s together with the variation of the height of fall between 0,6 and 166 cm a profound discussion of errors is necessary.     

Mechanische eigenschaften von polyesterfasern bei kurzzeitiger zugbeanspruchung, 4. Strukturveränderungen durch kurzzeitverformung an polyester-monofilamentgarn

Interferometric measurements of a PETP-monofilament yarn show that the orientation of the high pre-orientated material decreases after stretching and relaxing. The effect of desorientation is more distinctive by a slower deformation then by a high-speed deformation. The lower decrease is caused by a slower deformation. Material strained with a rate of 10⁴%/s shows “crazes” visible by interferometry. These “crazes” are not cracks but sites with lowered orientation. For slower deformation it is visible interferometrically that the orientation of the macromolecules in the fiber is asymmetric. DTA-curves from PETP-fibres show an exothermic peak between 30 and 80°C which can be related to specific structures of the non cristalline regions. By low-speed straining this peak shifts to lower temperatures. Stress-free storing of the material causes the peak to move back to the original temperature. For material deformated at high-speeds this peak does not change its position.     

Strukturabhängige Eigenschaften von Tensiden,untersucht an Reihen von 2-Alkylsulfaten,Phosphinoxiden und ω-H-Perfluorverbindungen

Structure-Dependent Properties of Detergents as Studied at 2-Alkylsulphates, Phosphine-oxides, and ω-H-Perfluoroalkyl Compounds CMC values from δ/lg c-curves were determined for the homologous series of 2-alkyl-branched alkylsulphates, dimethyl- an diethyl-phosphine-oxides and ω-H-perfluoroalkyl-sulfosuccinates. On this basis effective chainlengths were calculated and correlated with other properties as maximum of surface tension depression, wettability and foaming.     

Qualitätsbestimmende Eigenschaften bei der Verarbeitung von Rapssaat

Characteristics of Quality for the Processing of Rapeseed Among quality characteristics of oilseeds high extraction rates by the lowest possible technical expenses rank first for oilmilling. Apart from weight of cargo, oil content, humidity and contamination are therefore the most decisive determinants of price quotations. But for efficient oil extraction further criterions are essential such as structure and hardness of the seed, content of free fatty acids, phospholipids (gums), unsaponifiables, colour bodies or pollutants. In addition, the nutritional qualities of the meal, especially its content of glucosinolates and protein, deserve increasing interest. Each of these characteristics typically differs in its modificability by means of breeding and processing. From two experiments with industry scale processing of rapeseed from new varieties low in erucic acid and glucosinolate, results were obtained in 1975 and 1976 confirming the technological equivalency of the traditional and the new rapeseed varieties. Simultaneous genetic improvement of oil and protein content is limited by a negative physiological correlation between these two important quality characteristics. But probably the maximum capacity with regard to these traits is not yet realized in the present varieties. According to the results of an experiment with more than 4000 plants and their progenies progress in protein selection varies within different subgroups of a total of breeding stocks preselected for oil content and thousand-seed-weight, respectively.     

Mechanische Eigenschaften zyklisch be‐ und entfeuchteter Zeolithgranulate

The production of zeolite granules varies in the amounts of binder content and different drying/activation temperatures. Here, the influence of moisture content and cyclic moisture loading and unloading on the mechanical properties like the strength of three different types of zeolite granules has been studied by uniaxial compression tests. The force‐displacement curves and scanning electron microscopy pictures of the granule and fracture surfaces show that with increasing number of moistening‐drying cycles, a continuous decrease in the strength of granules take place due to non‐regenerative damage of the structure.     

Zur Produktgestaltung kohäsiver Pulver – Mechanische Eigenschaften,Kompressions‐ und Fließverhalten

Product Design of Cohesive Powders – Mechanical Properties, Compression and Flow Behavior The three yield conditions of a powder continuum (incipient yield, stationary flow, consolidation) are formulated on basis of particle mechanics by the model ?stiff particles with soft contacts“. So that the direct influence of contact behaviour on flow behaviour is analytically shown. The powder compression behaviour is characterised by a compressibility index. Additionally the compression rate and the specific compression work are explained. So that the correlation between contact compliance, adhesion force intensification and powder flowability can be physically consistent evaluated. The response functions of extreme stressing and flow conditions at material conversion processes, storage and transport can be sufficiently described by these models. Obviously, suitable conclusions may be also drawn to design marketable products of processing industries.     

Zusammensetzung,Präparation und Eigenschaften von Rapsphospholipiden

Composition, Preparation and Functionality of Rapeseed Phospholipids It is well known that phospholipids are byproducts of rape seed processing. Nevertheless they have only a small application field because of sensoric problems, undesirable colour and a lack of knowledge on relationship between structure and action. In this study the phospholipid composition of rape seeds of different breeding quality is characterized. The possibilities to prepare the main phospholipid constituents are analyzed. The functionality (interfacial behaviour) of phospholipid classes are tested in two experiments in order to receive more basic information on these compounds.     

Darstellung und Eigenschaften von Fettsäurepolyglykolestersulfaten

Production and Properties of Fatty Acid Polyglycol Ester Sulfates Fatty alcohol oxethylates, produced by reaction of fatty alcohols from hydrogenated fatty acid methyl esters with ethylene oxide, are the basic material for an important class of anionic tensides, the fatty alcohol ether sulfates. The fatty acid polyglycol ester sulfates are a very interesting alternative to the fatty alcohol ether sulfates. The former are available by saving hydrogenation, in principle directly by fatty acid oxethylation or interesterification of fatty acids with polyglycols, followed by sulfatation. We report about the production of fatty acid ester sulfates by sulfatation of the fatty acid polyglycol monoesters by sulfurtrioxide or chlorosulfonic acid. By means of the results of physicochemical measurements and process trials it is discussed how far fatty acid polyglycol monoester sulfates are suited as alternative tenside raw material fatty alcohol ether sulfates.     

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.     

Flexibilität und thermodynamische Eigenschaften von Polyacrylaten,Polymethacrylaten und statistischen Acrylat/Methacrylat-Copolymeren 2. knäuelparameter

Flexibility and interaction parameters of the polymers have been calculated from the results of light-scattering and viscosity measurements with polyacrylates, polymethacrylates and random copolymers of methyl methacrylate with acrylates and n-butyl methacrylate. Only slight differences are found when the chain rigidity of polyacrylates is compared with that of polymethacrylates. There is however a clearcinfluence of the ester alkylgroup. With increasing size of the ester alcohol the polymer chain gets more rigid. In case of copolymers the chain flexibility does not result simply from the homopolymer values. The measured values don't reveal a systematic connection, moreover in case of copolymers there is a strong influence of solvents on the unperturbed dimensions. The repulsive powers occuring in the copolymer coil due to hetero-contacts have been characterized quantitatively. The graduaeion which was found coincides with compatibility tests of the corresponding homopolymers in a concentrated solution : the more intense the expansion of the copolymer coil caused by heterocontacts, the lower the concentration where a demixing of the homopolymers is observed.     

Struktur und Eigenschaften von ABS-Polymeren, 13. Einfluß der Polymerisationsbedingungen auf die Struktur von ABS-Polymeren bei der Pfropfung in Emulsion

By grafting styrene-acrylonitrile onto poly(butadiene) latex graft polymers of different structure are synthesized. During the graft reaction the monomer to poly(butadiene) ratio and the conversion were varied and the influence of these variations on the degree of grafting and the molecular weight of grafted chains was studied. By mixing these graft polymers of different graft structure (graft density) with styrene-acrylonitrile-copolymers, ABS-materials are formed with a rubber content of 17.5% by weight. Glass transition temperature (T_g) of the elastomer phase of these ABS materials as well as notched impact values correlate with graft density of the rubber component.     

Eigenschaften und Wirkungen von Calcium-verseiften Palmfettsäuren im Verdauungstrakt von Wiederkäuern

Properties and Effects of Ca-Saponified Fatty Acids of Palm Oil in the Digestive Tract of the Ruminant Experiments in vitro applying the Rumen Simulation Technique (RUSITEC) and experiments in vivo with adult wethers and fistulated sheep were conducted to evaluate the effects of Ca-saponified palmoil fatty acid fat supplementations on digestive and physiological parameters in ruminant metabolism. There were only negligible effects of total volatile fatty acid concentration, digestibility of dietary fibrous components (ADF, NDF), retention time of rumen fluid and small feed particles during fat supplementation periods. Numbers of protozoa, ammonia concentrations, cellulolytic activity and the acetate/propionate ratio were however reduced by increasing tat supplementations. The ether-extractability of fatty acids was higher after incubation for several hours and in favour of more unsaturated fatty acids. The extractability of in situ (Nylonbag Technique) applicated Ca-saponified fatty acids was lower for adapted sheep than for sheep fed a standardized basal ration without fat supplementation.