Die Emulgierung oxidierter Polyäthylen-Wachse mit ionisch-nichtionischen Emulgator-Systemen

Emulsification of Oxidized Polyethylene Waxes with Ionic-Nonionic Emulsifier Systems The author reports on the emulsification of oxidized polyethylene waxes with varying acid values and molecular weight distributions. The emulsifier system comprised of predominantly a nonionic ethoxylated surfactant based on alkyl phenol in combination with a small amount of alkali hydroxide to which the water for emulsification was added. Emulsion properties, such as viscosity, pH-value, particle size (light transmission), and glaze of the dry films on plane surface, were used to formulate the optimum emulsifier systems. Thus, the optimum ratio of the components and the degree of ethoxylation of the nonionic surfactant were determined. Similarly, the method of emulsifying was optimized and the differences among the various existing polyethylene waxes were determined.     

Blends aus Polyvinylchlorid und chloriertem Polyäthylen. II. Morphologie von Blends aus Polyvinylchlorid und chloriertem Polyäthylen

Blends of poly(vinyl chloride) (PVC) and chlorinated poly(ethylene) (CPE) form a high impact polymer multiphase system. Characterization of this system by electron microscope becomes possible by a new pretreatment procedure of the polymer blend. The investigation of the morphology by this method shows the initial separation of secondary PVC particles (50–200 μm) into primary PVC particles (0,1–1 μm) by the soft CPE-phase. Due to the stability of the primary PVC-particles an interpenetrating network of the two phases is formed dependent on temperature and shear conditions of the melt Above a specific temperature PVC primary particles melt and the interpenetrating network is transformed into a system of fine dispersed CPE-particles in a PVC matrix Similar results are obtained in the system PVC/poly(ethylene-co-vinyl acetate) and PVC/poly(methyl methacrylate-co-butadiene-co-styrene).     

Neuartige emulgierbare Polyäthylenwachse

Novel Emulsifiable Polyethylene Waxes In comparison to naturally occuring waxes and their derivatives, the group of synthetically prepared emulsifiable polyethylene waxes known so far exhibit a relatively small proportion of polar centers in their molecular structure. Using a new process of preparation, products having a high content of hydrophilic groups are obtained. The properties and emulsifying techniques are described. This report also includes the development of a new group of purely non-ionic emulsifiable very hard polymer waxes.     

Schnellbestimmung monomerer,nicht oxidierter Fettsäuren

Quick Determination of Monomeric Unoxidized Fatty Acids Refining and distillation fatty acids as well as raw or partly refined oils can contain beside monomeric fatty acids di and polymeric as well as oxidized fatty acids, too. Determination of the content of monomeric, unoxidized fatty acids is important for the use in feed. As quick method a gas chromatographic procedure is presented. Collaborative studies demonstrate a satisfactory repeatability of the results. The comparability is impaired by apparatus and operating parameters. The relative constance of deviation permits a compensation by comparative analysis and determination of correction factors.     

Auswirkungen oxidierter Fettsäuren auf landwirtschaftliche Nutztiere bei Unterversorgung mit Vitamin E und Selen

Effects of Oxidized Fatty Acids on Agricultural Working Animals in Case of Insufficient Supply with Vitamin E and Selenium Diseases of agricultural working animals due to insufficient supply with vitamin E and selenium have been common knowledge for long. Especially in case of feeding with oxidized fats, rich in polyenic acid significant defects can occur. It could be detected in special tests with trouts (Salmo gairdnerii R.) that a low degree of oxidation (about POV 50) of the feed fat in case of sufficient supply with vitamin E and selenium is without any influence on growth and feed exploitation. Higher oxidized fats (about POV 250 and more) cause less increase in weight and above all defects on organs, which can be detected among others by certain parameters (haematocrit value, haemoglobine content, GOT, GPT, LDH, CK, Bilirubin). These effects can be avoided by higher doses of tocopherol. It exists, however, a dependency between the uptaken amount of fat and the period of additional feeding. A mixture of natural D-tocopherols in rations with high oxidized polyenic acids (POV 900–1700) was able to decrease or to avoid the noxious effect and losses of animals if the additional amount was increased. It turned out that there was an equivalency to D, L-α-tocopherol, even if there were great differences in the tocopherol equivalences.     

Bestimmung von Polyäthylen in vernetzten Mischungen aus 1,4-Polybutadien und Polyäthylen mittels Olefin-Metathese

Mixtures of 1,4-polybutadiene and polyethylene were crosslinked by dicumylperoxide. Then products were degradated by olefin metathesis with 2-octene using a WCl₆/C₂H₅AlCl₂ catalyst. The remaining solid polyethylene was determined.     

Untersuchungen zur Langkettenverzweigung in Polyäthylenen

Polyethylene samples of various densities and melt flow indices resulting from different polymerization processes have been investigated with respect to long chain branching (LKV). For that purpose several polymer fractions have been characterized by measurement of weight average molecular weights M_w and intrinsic viscosities [η], the latter ranging from 0,2 to 3,2 with high pressure samples and from 0,2 to 10 with low pressure material. The intrinsic viscosity difference of branched (high pressure) polyethylene compared to linear (low pressure) polyethylene is used as a measure of LKV. With high pressure polyethylene LKV increases with decreasing density. This dependence is strongest within the medium molecular weight range. Samples with varying LKV but constant density can be obtained by appropriate change of polymerization conditions. No LKV has been observed with low pressure polyethylene. This means a marked difference compared to high pressure material of equal density. Branching with low pressure polymers can therefore be ascribed to the short chain type only, which in particular results from copolymerization. Several mathematical approaches have been checked whether or not they can yield suitable information about n, the number of long chain branches per molecule. The best fit with our experimental data is obtained using the expression [η]v/[η]₁ = g^1,3 (n = f(g)) and assuming, that the average concentration of long chain branch points does not depend on molecular weight for fractions of the same sample (n/M = const.). If LKV ist taken into consideration, logarithmic normal molecular weight distributions are obtained for many high pressure polyethylenes (similar to low pressure material). Data are reported in support of the view, that performance characteristics are dependent on LKV. There is some evidence, that melt flow properties of polyethylene are improved with increasing LKV.     

Die mit Natriumphenolat katalysierte Addition von Äthylenoxid-Propylenoxid-Gemischen an Monophenylmonoalkylenglykole. II. Die Kinetik der Äthylenoxid-Propylenoxid-Addition an Monophenylmonoäthylenglykol

The dependence of insertion-type addition of ethylene oxide/propylene oxide mixture to monophenyl monoethylene glycol on monomer ratios was investigated. An attempt to determine the reactivity parameters by MAYO and LEWIS method was discarded on account of differing dimensions shown by the rate constants of separate reactions. A rate law to describe the consumption of ethylene oxide has been presented. The dependence of relative reaction rates on the-mole ratios shows preference for addition of ethylene oxide; however, rise in reaction temperature exercises no appreciable effect on the preferred addition.     

Zur Bestimmung von Polyäthylen in Fetten

Determination of Polyethylene in Fats Numerous procedures, based on the same principle have been suggested for the determination of polyethylene in crude animal fats for technical uses. Investigation of these procedures led to the development of a gravimetric method of determination, which is based on the latest suggestion of the British Standards Institution. This method enables, apart from determination, the identification of the synthetic polymer by infrared spectrometry. Out of known amounts of added polyethylene, 90 or 295 mg/kg of pure beef tallow, 96–97% were recovered. The incidental errors were at the most 10 mg/kg at the lower level of contamination and 6 mg/kg at the higher level. The values are mainly influenced by the limitation in attainable weight constancy of the filtering device.     

Die Isomerisierung des Linolsäuremethylesters mit Rhodiumkomplexen

The Isomerisation of Linoleic Acid Methyl Ester with Rhodium Complexes The isolated double bonds of the linoleic acid methyl ester were conjugated with rhodium complexes plus SnCl₂ · 2H₂O as catalysts. The dependence of the reaction on phosphorous and nitrogen ligands was studied. The most active catalyst resulted with tri-p-tolyl-phosphin as ligand; it isomerises the linoleic acid ester in a good yield at temperatures as low as 25°C.     

Die Leistungsfähigkeit von Winterrapssorten mit 00-Qualität

Performance of Winter Rape Seed Varieties with Double Quality After realization of the first quality characteristic — exemption of erucic acid — of rape seed in 1974, rape seed cultivators work at the second quality characteristic, the exemption of glucosinolates. The attempts resulted 1981 in the introduction of the first winter rape seed variety with double quality LIBRADOR in the German list of varieties. Already one year later — 1982 – the variety LIGLANDOR followed, and 1983 the varieties LINDORA, LIROPA and ELENA were taken up in the list. The difference in the performance between the 0-varieties and the 00-varieties decreases with every new variety introduction. The difficulty of testing the performance, caused by animal feed, led to the fact that the spread of the results between the 00-varieties is essentially higher than between the 0-varieties.     

Differentialthermoanalytische Untersuchungen zur effektivität einiger Stabilisatoren bei Polyäthylenterephthalat

The thermooxidative resistance of poly(ethylene terephthalate), synthesized in the presence of different stabilizers as well as combinations of stabilizers as well as combinations of stabilizers, is studied with the help of the dynamic and isothermal DTA-method. The stabilization coefficients (by the dynamic DTA) and the characteristic induction periods (by the isothermal DTA) are determined. A good correlation is established between the data obtained by both methods.     

Bestimmung von Aminoendgruppen in ionisch gefärbten Polyamidfasern durch Ionenaustausch

The method under discussion allows the determination of aminoendgroups in acid dyed polyamide 6 and polyamide 6.6 fibres. The dyestuff is removed from the solution of the dyed fibre by treatment with an ionexchanger. The free aminogroups can be determined afterwards by potentiometric titration. Under the conditions of the resin-treatment a hydrolysis of the amidebond, a cleavage of chainregulators and an adsorption of the polymer can be excluded. Spinning preparations interfere with the determination. Their influence can be diminished by extraction with polar solvents. Dyed samples show a greater content of aminoendgroups, this can be explained by hydrolysis of the polyamide during dyeing, catalyzed by the dyestuff.     

Die Qualitätskontrolle von Emulsionen mit Hilfe des Leitfähigkeitsspektrums

Quality Control of Emulsions with the Conductance Spectrum A method for characterising and identifying of emulsions is described. By means of a special method conductance spectra can be plotted. The quality of the products concerning the dispersed phase, can be defined and tested in the field of quality control. The specifity of the method is shown by the examples of some O/W- und W/O-emulsions.     

Die reaktion von diandiglycidyläther mit aromatischen diaminen

m-Phenylendiamine, p,p'-diaminodiphenylmethane and p,p'-diaminodiphenylsulphone were evaluated as hardeners for low molecular weight epoxide resins, and basic physical constants characterizing the kinetics of the reaction of diglycidylether of diane with the above hardeners were determined. Using the relation between viscosity, average molecular weight, and degree of reaction it was possible to characterize the existence range of the so-called epoxide-pregels which are formed from mixtures of epoxide resins with aromatic amines at lower temperatures. The applicability of SMITHS equation related to the kinetics of reaction between epoxidic compounds and amines was verified. The kinetic of reaction indicates the existence of hydrogen bonds at the epoxide groups, it may be assumed, however, that the presence of these relatively strong intermolecular bonds affects even the rate of pregelation.     

Modelluntersuchungen zur Wirkungsweise von Oxidationsstabilisatoren für Polyäthylenterephthalat

The behaviour of some stabilizing additives to poly(ethylene terephthalate) (PETP) is studied in the model oxidation reaction of isopropylbenzene. On the basis of the course of accumulation curves for cumene hydroperoxide conclusions were drawn for the way of formation and consumption of hydroperoxides in the presence of different types of stabilizers and combinations of stabilizers under investigation.     

Polyätherester-Block-Copolymere – Eine Gruppe neuartiger thermoplastischer Elastomerer

High melting polyether esters can be prepared by ester interchange from readily available starting materials such as dimethyl terephthalate, polyalkylene ether glycols and linear short chain diols. The resulting block copolymers exhibit a continuous two-phase domain structure consisting of amorphous polyether ester soft segments and crystalline short chain polyester hard segments. By proper selection of the relative amounts of polyether and polyester segments, polymers ranging from fairly soft elastomers to impact resistant elastoplastics may be obtained. The preparation, morphology and physical characterization of polyether esters as well as the effect of the structures of the soft and hard segments on polymer properties are described. Polytetramethylene terephthalate based on polyether esters are particularly suited as thermoprocessable high performance elastomers offering an unusual combination of physical and chemical properties characterized by high abrasion, tear and solvent resistance as well as excellent low and high temperature properties. Because of their good melt stability, low melt viscosity and high crystallization rates, these polymers can be processed within a wide temperature range by all methods commonly used in the plastics industry.     

Massenspektrometrischer Nachweis des cyclischen Trimeren im Polyäthylenterephthalat

By direct pyrolysis of commercial polyethyleneterephthalate in the mass spectrometer a content of about 1% of the cyclic trimer ethyleneterephthalate is indicated at temperatures below thermal degradation of the polymer. The comparison with EI- and FD-mass spectra of the authentic cyclic trimer allows its identification without previous isolation.