Umweltverhalten und Toxikologie der Wachse

Environmental Behaviour and Toxicology of Waxes Plant and animal waxes are chemically relatively stable nontoxic substances and are used by humans since ages. In the nature waxes have protective function against environmental influences. This protective action is possible due to great resistance of the waxes towards environment, which also means low biological degradability. Obviously, waxes are undigestible and non-toxic in human and animal organism. Partially synthesized waxes based on montana wax, a plant fossil wax, have a structure similar to natural waxes, and therefore they resemble natural waxes with regard to environmental behaviour and are fully harmless from toxicological viewpoint. Also fully synthetic waxes, such as polyethylene waxes and polyethylene oxide waxes have, according to results obtained so far, no undesirable effects on environment. Waxes have been approved in foods worldwide, obviously due to their favorable toxicological properties.     

Wax composition of sunflower seed oils

Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C₄₀−C₄₂ fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing.     

Wachssynthese mittels der Guerbet-Reaktion

Synthesis of Waxes by Guerbet Reaction Branched chain waxes possess better liquifying properties and superior solubility in organic solvents than straight chain waxes. Branched chain waxes having both of the above properties were therefore synthesized by a new principle, namely the Guerbet reaction. Guerbet alcohols, based on technical octadecyl alcohol were esterified with various mono- and dicarboxylic acids. Strongly branched and relatively low melting waxes were thus obtained which, inspite of their greater solubility in organic solvents, exhibit insignificant liquifying effect in wax pastes. As against these, when the Guerbet alcohols from stearyl alcohol are oxidized, branched chain wax alcohols are obtained which in native as well as saponified state show liquifying action on wax pastes. The Guerbet reaction is explained taking the example of a mixture of two primary alcohols.     

Natural montan wax and its raffinates

Natural waxes have been used by mankind since prehistoric times. Many uses of wax are based on the imitation of its natural functions. Waxes in nature primarily serve to provide protective barriers on the surfaces of living organisms. Their functions are also determined by wax characteristics such as adhesion and cohesion, as well as slip and deformation effects. In ancient times, for example, wax seals were used to help preserve food and beverages. Beeswax has remained an important material for manufacturing candles up to the present day. Recent vegetable waxes have been used in industry since the mid‐nineteenth century, for example in care products. Refined and chemically processed montan‐based waxes are quite similar to naturally occurring vegetable ester waxes in their structure and application characteristics. They are similar in their environmental characteristics and are also nontoxic. Crude montan wax itself belongs to the naturally occurring waxes of vegetable origin such as candelilla wax and carnauba wax.     

Gas-chromatographische Untersuchung von Naturwachsen

Gas Chromatographic Investigation of Natural Waxes A rapid gas chromatographic method for the identification of natural Waxes is described, according to which the wax acids and the unsaponifiables are investigated after saponification. The methyl esters of the wax acids as well as the acetates and oxidation products from the unsaponifiables showed a characteristic pattern of distribution amongst the individual natural waxes. In the characterization of natural waxes it is desirable to investigate the methyl esters of the wax acids, because after saponification the wax acids are obtained as a more uniform class of substances than the unsaponifiables.     

Chemometric Classification of Comb and Cuticular Waxes of the Honeybee Apis Mellifera Carnica

Waxes are important as building material and for the chemical communication of the honeybee Apis mellifera carnica. In this study chemometric tools were established for classifying the different waxes inside the hive. By using gas chromatography in combination with mass spectrometry, components of different types of waxes were analyzed. By considering different substance classes of waxes, discriminant function analyses revealed distinct subtypes of comb waxes and of cuticular waxes. It is shown that the aging of comb wax is in part a spontaneous physicochemical process due to differential volatilities of compound classes with different chain length ranges. On the other hand it is directly influenced by the bees by adding lipolytic enzymes to the comb wax. The data suggest that the varying cuticular wax and comb wax compositions could serve as cues for bees to recognize castes, sexes, or comb age.     

Wachse mit hoher Dispergierfähigkeit unter besonderer Berücksichtigung ihrer Eignung für die Herstellung von Kohlepapierfarbmassen

Waxes Having High Dispersibility and Special Consideration of Their Suitability in the Manufacture of Colouring Masses for Carbon Paper Increasing amounts of waxes having fundamentally different chemical composition are being used as dispersion aids. In the manufacture of colouring masses for carbon papers, the materials used as vehicle of the colour and as dispersing agent for carbon black are hydrocarbons, wax acids and their natural esters. Whereas low-priced paraffins are mainly used for cheap carbon papers meant for a single use, carnauba wax is used for better quality carbon papers which can be used several times. The latter wax is especially suited because of its carbon black-dispersing and oil-binding properties. Since crude montana wax does not have these properties to such an extent as the carnauba wax, it was attempted to improve the carbon black-dispersing and oil-binding of montana wax by chemical synthesis. This was achieved by reacting crude montana wax with maleic anhydride and subsequent esterification of the reaction products with glycols. The results were successfully applied to the solution of problems involving dispersion of pigments and plastic additives.     

The composition of beeswax and other waxes secreted by insects

This review deals, with waxes of members of two quite different groups of insects, the bees and the scale insects, which secrete large amounts of wax. The former use was as a structural material and the latter as a protective material. The compositions of waxes from some of these insects are described and particular attention is paid to the compositions of the unhydrolyzed waxes and to the presence of hydroxy acids. New analyses of beeswax and of wax of a species of bumble bee are reported. The structures of the diesters, hydroxyesters and diols of beeswax are elucidated. The bumble bee wax contains major proportions of saturated and unsaturated hydrocarbons, and of long chain saturated, mono- and diunsaturated esters. The relationship between structure and function of the waxes is discussed. Issued as National Research Council of Canada No. 11260. One of six papers to be published from the Symposium on Natural Waxes, presented at the AOCS Meeting, San Francisco, April 1969.     

Dünnschicht-Chromatographie von Kohlenwasserstoff-Wachsen an harnstoffbeschichteten Platten

Thin-Layer Chromatography of Hydrocarbon Waxes on Plates Coated with Urea Chromatographic mobility patterns of hydrocarbon waxes on normal silica gel G and urea-impregnated silica gel G plates are compared. Influence of polarity and temperature of the developing solvent, and effect of chain length and degree of branching of the wax on separation were investigated. The varying tendency of the wax components to form inclusion compounds with urea result in considerable difference in mobility patterns. Thus the various hydrocarbon waxes can be better differentiated.     

Wax analysis of vegetable oils using liquid chromatography on a double-adsorbent layer of silica gel and silver nitrate-impregnated silica gel

A chromatographic method is described to measure the crystallizable wax content of crude and refined sunflower oil. It can also be applied to any other vegetable oil. The preparative liquid chromatography step on a glass column containing a silica gel adsorbent superimposed upon a silver nitrate-impregnated silica gel support is used to isolate a wax fraction which is then analyzed by gas chromatography. The recovered wax fraction contains, in addition to the crystallizable waxes, hydrocarbons and other compounds with gas chromatographic retention times corresponding to waxes with chain lengths C₃₄−C₄₂. These compounds are short-chain saturated waxes in fruit oils, such as grapeseed and pomace. In seed oils such as sunflower, soybean or peanut, the compounds initially referred to as “soluble esters” are identified as monounsaturated waxes, esters of long-chain saturated fatty acids, and a monounsaturated alcohol, mainly eicosenoic alcohol. Such waxes are absent from corn or rice bran oils.     

Analyse von Wachsen und Wachsmischungen mit Hilfe der Dünnschicht-Chromatographie

Analysis of Waxes and Mixtures of Waxes by Thin-Layer Chromatography A few commercial waxes were investigated by thin-layer chromatography. The following mobile phases and temperatures were employed: benzene, benzene + 0.5% acetic acid and benzene + 2% methyl acetate at 45°C; tetrachloroethylene at 80°C and tetrachloroethylene + 0.5% acetic acid at 70°C. A few examples showing the possibility of analyzing wax mixtures with the help of the methods described here, are given.     

Plant waxes

The surface of plants is covered with a complex mixture of lipids, often in crystalline form, called plant waxes. The chemistry, biosynthesis, catabolism and function of plant waxes are reviewed. The most common components are hydrocarbons, wax esters, free fatty alcohols and acids. Ketones, secondary alcohols, diols, aldehydes, terpenes and flavones are also found. The major function of the wax appears to be protection of the organism from water loss and other hazards of the environment. The alkanes are formed from fatty acids either by elongation followed by decarboxylation or by head-to-head condensation between two biochemically dissimilar fatty acids followed by specific decarboxylation of one of them. Fatty acyl-CoA is reduced to the aldehyde which in turn is reduced to the alcohol. The alcohol is then esterified with acyl moieties from acyl-CoA or phospholipids. Plant waxes undergo very little catabolism in plants but animals can degrade them to a limited extent and microorganisms readily degrade them. One of six papers to be published from the Symposium on Natural Waxes, presented at the AOCS Meeting, San Francisco, April 1969.     

A new test method for determination of wax content in crude oils,residues and bitumens

A new method for determining wax content in petroleum materials is developed. It is based on thin layer chromatography with flame ionization detection (TLC-FID) and involves two-step development with two solvents. The principle of the test method is first to separate saturates from other more polar components based on good solubility of saturates in n-heptane and weak strength of interaction with an adsorbent (silica). Waxes are then separated from the saturate fraction using a poor solvent methyl-ethyl ketone (MEK) at such a low temperature (typically ?20 °C) that waxes are in solid state. The separated fractions are quantified with FID. The test method is verified using various model compounds including n-alkanes of different molecular weight, isoalkane, as well as commercial waxes. Results indicate that the TLC-FID method detects the waxes mainly composed of n-alkanes ranging from C20 to C40, and large isoalkanes and cycloalkanes which are soluble in n-heptane. The method has been satisfactorily applied to a variety of samples of crude oils, residues, and bitumens. It is simple, quick, and reliable. By changing MEK temperature in the development chamber, waxes may be further characterized.     

Wachse als Scheuerschutz in Druckfarben

Waxes as Abrasion-Protective Agents in Printing Inks In printing ink industry, the current trend is towards the use of waxes, which are well known as abrasion-protective agents, in the form of fine powder rather than in preparations containing solvents and varnishes. In the present work, influence of the type of wax, particle-shape and particle-size distribution on the effects achieved with various printing ink systems is shown.     

Separation and Analysis of Wax from Egyptian Sugar Cane Filter Press Cake

Waxes from filter press cake of the by-product of the Sugar Cane Industry gained from various Egyptian Cane Sugar Factories were studied. A method for continuous extraction of wax filter cake using different solvent i. e. toluene, naphtha, acetone, fractionated gasoline, denatured and refined alcohol was investigated. The speed and ease of extraction using different solvents were compared. By using toluene as solvent the highest percentage of crude wax was obtained from Edfu, which gave 14.55%, while extraction with refined alcohol produced 12.65% crude wax from Qus. Decolorization of crude wax was carried out by sodium hypochlorite, nitric acid, chlorine, sulphur dioxide and acetone. The pure wax was separated from the fatty oil fraction by fractional crystallization from 70° to 0° C. The greater portion of wax can be obtained at 30° C. Hard, brittle wax was obtained between 45° to 20° C. The crude and refined waxes had properties comparable to carnauba wax and other commercial waxes. The Egyptian cane sugar waxes can be utilized in paper, ink, coating, varnishes, pharmaceuticals, cosmetics and fertilizer industries.     

Wachse für die Zitrusfruchtbeschichtung

Waxes for Citrus Fruit Coating In the last years waxes basing on polyethylen have got a great importance in the field of citrus fruit coating. The propitious physiological and processing properties of these waxes were supposition for this development. Polyethylen wax coatings effect e. g. a reduction of water vapour permeability and lost of weight, an improvement of gloss, influence on respiration and the internal oxygen and carbondioxide content of the fruit.     

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.     

Bestimmung funktioneller Gruppen in oxidierten Paraffinwachsen

Determination of Functional Groups in Oxidized Paraffin Waxes Methods are described for the quantitative determination of alcohols, esters, carbonyl compounds, acids and peroxides in oxidized paraffin waxes. When analysing for alcohols, the hydroperoxide content of the wax must be taken into account in the final calculation whereas the peroxides must be reduced before determining the ester and carbonyl compounds. Without these measures values are found which are too high.     

Textural and Physical Properties of Biorenewable “Waxes” Containing Partial Acylglycerides

Vegetable oil-based “waxes” are a promising alternative to beeswax and paraffin wax, the usual raw materials for candles and encaustic painting, because they are environmentally friendly, less expensive than beeswax and more biodegradable than paraffin. In this study, wax mixtures of mono- (MAG) and diacylglycerides (DAG) of fully hydrogenated vegetable oil were prepared at various ratios and their textural properties were compared to beeswax. Waxes having 30–40% of DAG were softer and more cohesive than those having other proportions of DAG, and their values were the closest to those of beeswax. A wax mixture of 70% MAG and 30% DAG (MDWAX) was then treated with various additives, including free fatty acid, fatty alcohol, hydroxy triacylglycerides (OHWAX), dammar resin, and acetylated monoacylglycerides (AM). The 1:1 (wt.) mixture of MDWAX and AM (referred as 50% AM) had similar plasticity to that of beeswax, and a high textural stability during one-month storage. The melting and crystallization properties of the wax containing 10% OHWAX and 90% MDWAX had close similarity to those of beeswax. The crystal form in most formulated waxes was β′ as determined by X-ray diffraction. However, the 50% AM wax had α and β polymorphs in equal proportions and the MDWAX had only β form crystals. The crystallinity of all formulated waxes was lower than those of beeswax and paraffin. Polarized light microscopy images revealed that the microstructures of formulated waxes were different from that of beeswax. For sensory evaluation, the order of the surface buffability was determined as MDWAX+10% Dammar < MDWAX < MDWAX+50% AM < paraffin < beeswax.