Versuche mit zur Produktion von Erucasäure geeigneten Kulturarten

Experiments with Oilseed Crops for the Production of Erucic Acid The Brassica-species are well suited for the production of erucic acid as industrial raw-material. The five crop species Indian mustard (Brassica juncea), Äthiopian mustard (Brassica carinata), Crambe (Crambe abyssinica), oilseed radish (Raphanus sativus ssp. oleiformis) and rocket (Eruca sativa) were tested for agricultural and seed quality characteristics. The results of the primary evaluation showed that quality is sufficient in all crops besides oilseed radish; however the starting yield level is only satisfying in Indian mustard and Crambe. It was possible to increase yields significantly in crossing progenies. As all species are summer types, their yield potential ist naturally lower than that of winter rapeseed.     

Zur Konstitution der Reaktionsprodukte aus Phenacylthioglykolsäure und Benzylmercaptan sowie aus Phenacylbenzylsulfid und Thioglykolsäure

On the Structure of the Reaction Products from Phenacyl Thioglycolic Acid and Benzyl Mercaptan and from Phenacyl Benzyl Sulfide and Thioglycolic Acid Phenacyl benzyl sulfide gives with thioglycolic acid the expected mercaptol C₆H₅C(SCH₂COOH)₂CH₂SCH₂C₆H₅ ( 5 ) as the only reaction product, while phenacyl thioglycolic acid and benzyl mercaptan give the mercaptol C₆H₅C(SCH₂C₆H₅)₂CH₂SCH₂COOH ( 6 ) as well as the mercaptal C₆H₅CH(SCH₂C₆H₅)Ch(SCH₂C₆H₅)₂ ( 4 ). The reactions took place in presence of hydrochloric acid. On the basis of the synthetic and the n.m.r. spectroscopic studies the reaction mechanisms are discussed.     

Zur Konstitution des Reaktionsproduktes aus Phenacylthioglykolsäure und Thioglykolsäure

On the Structure of the Reaction Product from Thioglycolic Acid and Phenacyl Thioglycolic Acid The reaction product obtained from phenacyl thioglycolic acid and thioglycolic acid is shown to represent 1,1,2-tris-(carboxymethylthio)-2-phenylethane 4 , and not 1,1,2-tris-(carboxymethylthio)-1-phenylethane 3 as suggested earlier in the literature. Analogously, phenacyl benzyl sulfide 2 and benzyl mercaptan yield 1, 1, 2-tris-(benzylthio)-2-phenylethane 5 . The reaction mechanisms are discussed on the basis of synthetic and n.m.r. spectroscopic studies.     

Wachstumsmechanismen bei der Lösungskristallisation von Stearinsäure aus Alkanen und Ketonen

Growth Mechanisms in the Crystallization from Solutions of Stearic Acid from Alcanes and Ketones The kinetics of the crystallization from solutions is governed by the transport phenomena for mass and heat as well as the interface processes. In the present work the kinetic data for the growth of stearic acid from alcane and ketone solutions are discussed. The acid serves as a model substance for long chain compounds. Its molecular properties are simple enough to be easily understood. The growth kinetics was measured as a function of supersaturation and temperature. The data were used to define a criterion for the comparison of the interface kinetics between different solvents and different substances. In addition the data are used to derive the molecular mechanisms of the growth. As a result, surface diffusion seem the most probable mechanism.     

Zusammensetzung und Anwendungen von Isostearinsäure

Composition and Application of Isostearic Acid The clay catalysed oligomerisation of unsaturated fatty acids yields C36 dimer fatty acids, C54 trimer fatty acids and C18 monomer fatty acids. Monomer fatty acids, which consists mainly of straight, branched, saturated and unsaturated fatty acids, can be distilled from the higher molecular weight products and after hydrogenation separated into solid stearic acid are mono- and polybranched C18 fatty acids whose branching points are mainly concentrated in the center of the molecule. Depending on the nature of the used raw materials and the degree of refinery, straight chain fatty acids, cyclic fatty acids, γ-lactones, unsaponifiable and even rosin acids are found as impurities. The low cloudpoint, comparable with oleic acid, as well as the excellent temperature- and oxidation stability gives isostearic acid and their derivatives excellent opportunities in applications as cosmetics, lubricants and plastics.     

Systeme zum Ein- oder Austrag von Schüttgütern in oder aus Druckräumen

Systems for the charging or discharging of bulk solids into or out of pressure chambers. In many branches of chemical and dressing technology there are compelling thermodynamic or economic reasons for carrying out various processes at pressures deviating from ambient values. If the reactants and products of these processes are dusts or granular solids then numerous problems are encountered on transfer between regions of higher or lower pressure. On the one hand, the properties of the feed (such as particle size, flow behaviour) should undergo the slightest possible modification, and on the other hand the transport of the material between the regions of differing pressure should be as continuous as possible. Moreover, the gas transport should be kept low. Pressure swing in the process region is to be avoided. The aim of this study was to survey all systems suitable for introduction or removal of bulk solids into or out of chambers at pressures other than the ambient value. The various pressure locks are assessed qualitatively for given tasks. A new solution is presented for the discharge of filter cake from high-pressure chambers.     

Glas- und tieftemperaturrelaxation von copolyestern der terephthalsäure

The relaxation mechanisms of linear saturated copolyesters of terephthalic acid are influenced by the chemical structure of the used aliphatic, aromatic, and cyclic diols or dicarbonic acids. The glass transition temperatures of the copolyesters are in the range from -30 to 90°C. The numerical value of T_G can be calculated by the increment method with a mean error of ±5°C. Since this method can be applied also to other polymer systems or some other physical parameters a general procedure for optimizing the increments is given. With reference to known relaxation criterions the molecular motions of the copolyesters above and below T_G are identified. The two relaxation mechanisms below T_G show a statistical distribution of the different components of acids and diols along the chain. The γ′-relaxation is caused by orientational motions of carbonyl groups and depends on the chemical structure of the neighbouring segments. On the contrary the γ″-process is not influenced by the molecular environment and is caused by hindered rotation of CH₂-groups.