Fischer-tropsch waxes. II. Crystallinity and physical properties

The density, congealing point, and hardness were considered in relation to crystallinity, determined by an infra-red spectrometric method, of a series of waxes which are fractions from crude Fischer–Tropsch wax. Values ranging between 65 and 93, expressed as molecular percentages of crystalline material present, have been obtained. Data on molecular weights and physical properties were available. Smooth curves could be drawn for the variations of density, congealing point and hardness (or rather penetration) with molecular weight, but only for the more highly crystalline waxes. Two waxes, with crystallinities below 75, were found to have abnormally low congealing points and densities and to be abnormally soft, in relation to their molecular weights. This can be explained in terms of the less dense packing of molecules in the amorphous state. The effect of crystallinity on density was examined more closely, and a set of equations expressing the relationship between these entities and molecular weight was derived. These contain an unknown factor, however, which is dependent upon molecular weight distribution.     

Photoelectric color measurements

Precision color measurements of oils, fats, waxes, etc. can be made with a Photoelectric Spectrophotometer, and their absorption or reflection determined with a degree of exactness not possible with any visual method. Oils of similar chemical constitution, although widely different in color, give similar spectral absorption curves. Oils of dissimilar chemical constitution, although alike when measured on the Lovibond scale, give dissimilar spectral absorption curves. This photo-electric method of measuring color may enable the oil chemist to make use of a method of color measurement that will disclose fundamental data.     

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.     

Chemical composition of the preen gland secretions from some ciconiiform birds

The preen waxes from four Ciconiiformes species are shown to be ester waxes of very different composition. Three species possess monoester waxes with branched wax acids and alcohols. In one of these waxes, homologous series of ethyl-substituted constituents are observed. In contrast to this, the uropygial gland secretion of the marabou is a triglyceride mixture.     

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.     

Über Modellwachse für den Metallpräzisionsguß

The Model Wax for the Precision Metal Castings After a short review of the history and the technique of precision metal casting on lost model waxes, the requisite properties of such waxes are given in details. The sum of all these properties can be achieved only by mixing different types of waxes with one another or by combination with other substances. At the same time, the molecular structure of the waxes also plays an important role. The relation between this and the shrinkage is shown by means of experimental investigations on a number of examples.     

Studies of the refractive indices of binary wax mixtures

Summary The greatest deviations in refractive index from ideal behavior of the binary wax mixtures are obtained with mixtures of vegetable waxes. These are waxes with higher unsaturation, waxes containing a higher percentage of hydroxy esters, and waxes containing glycerides or combinations of these. Melting points and refractive indices at the melting points can be determined simultaneously with the Abbe-56 refractometer.     

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.     

Organogelation Capacity of Epicuticular and Cuticular Waxes from Flax and Wheat Straws

Valorization of the agri-food industry by-products could contribute to curb issues related to food security and environmental problems. Flax and wheat seeds are major products of this industry, but their production is associated with tons of straws that can be valorized for their cuticular and epicuticular waxes. We aimed to determine the organogelation capacity of epicuticular waxes in comparison to cuticular waxes from both flax and wheat straws. Epicuticular waxes from flax and wheat straws have structured canola oil at 2% and 4% (w/w), respectively, whereas cuticular waxes from flax and wheat straws required critical concentrations of 4% and 5% (w/w), respectively. Characterization of the organogelation capacity (onset of crystallization temperature, temperature of phase transition, crystal morphology, solid fat, crystalline structure, and oil binding capacity) was also carried out. The high onset of crystallization temperature (38.1 ± 1.2°C), the phase transition at high temperature (38 ± 1.5°C), and capacity to structure canola oil at low concentration showed that epicuticular wax from flax straw is a promisor fat substitute, presenting organogelation properties comparable to the best results obtained in the literature for other vegetal waxes.     

Epichlorhydrin in der Wachssynthese

Epichlorohydrine in the Synthesis of Waxes Waxes that are soluble in usual wax solvents are of interest in special fields of application. It is not possible to prepare clear solutions of appreciable concentration using natural waxes, such as carnauba wax or derivatives of montana wax. Although these waxes are well soluble when hot, however, on cooling they separate out as crystalline or pasty masses. For preparing easily soluble waxes a new path of synthesis was found. Thus, waxes having ether or ester groups which were also easily soluble in the cold were prepared by reacting epichlorohydrine with such compounds, which, apart from having a long hydrocarbon chain also possessed a functional group with one active hydrogen atom.     

A rapid,effective method for the reduction of waxes in sunflower seed oil

Four samples of sunflower seed were surface washed with boiling hexane to remove waxes and hydrocarbons. Measurement of waxes in oil extracted from washed and unwashed seed showed greater than 92% removal of waxes. In addition, straight chain hydrocarbon content of the oil was substantially reduced. The composition of the material removed is shown.     

The Extended Community-Level Effects of Genetic Variation in Foliar Wax Chemistry in the Forest Tree <Emphasis Type="Italic">Eucalyptus globulus</Emphasis>

Genetic variation in foundation trees can influence dependent communities, but little is known about the mechanisms driving these extended genetic effects. We studied the potential chemical drivers of genetic variation in the dependent foliar community of the focal tree Eucalyptus globulus. We focus on the role of cuticular waxes and compare the effects to that of the terpenes, a well-studied group of secondary compounds known to be bioactive in eucalypts. The canopy community was quantified based on the abundance of thirty-nine distinctive arthropod and fungal symptoms on foliar samples collected from canopies of 246 progeny from 13 E. globulus sub-races grown in a common garden trial. Cuticular waxes and foliar terpenes were quantified using gas chromatography - mass spectrometry (GC-MC). A total of 4 of the 13 quantified waxes and 7 of the 16 quantified terpenes were significantly associated with the dependent foliar community. Variation in waxes explained 22.9% of the community variation among sub-races, which was equivalent to that explained by terpenes. In combination, waxes and terpenes explained 35% of the genetic variation among sub-races. Only a small proportion of wax and terpene compounds showing statistically significant differences among sub-races were implicated in community level effects. The few significant waxes have previously shown evidence of divergent selection in E. globulus, which signals that adaptive variation in phenotypic traits may have extended effects. While highlighting the role of the understudied cuticular waxes, this study demonstrates the complexity of factors likely to lead to community genetic effects in foundation trees.     

Influence of natural additives and those synthesized by the Fischer-Tropsch method on the properties of petroleum bitumen and quality of floated asphalt

Introducing additives in BDUS 70/100 petroleum bitumen results in a high-quality binder for the preparation of floated asphalt with improved performance. Effective additives include amide waxes, natural waxes, high-molecular paraffins obtained from CO-hydrogen mixtures by the Fischer-Tropsch method, and also mixtures of high-molecular paraffins and polyethylene waxes.     

橡胶防护蜡的作用机理及影响其防护性能的因素

结合橡胶防护蜡的作用机理说明橡胶制品环境温度、石蜡化学组成、硫化胶交联度、石蜡内部迁移、胶料配合剂和石蜡浓度是直接影响防护蜡性能的因素。指出改性防护蜡是今后橡胶防护蜡的一个发展方向。     

Crystallization of waxes in sunflowerseed oil: Effects of an inhibitor

The mechanism of action of a commercial inhibitor on the crystallization of waxes present in sunflowerseed oil was analyzed. The results showed the inhibitor favored nucleation, leading to a decrease in the amount of waxes available for the growth of the crystals already formed. The inhibitor decreased the crystal size, increased the number of crystals and possibly caused slower crystallization of waxes.     

蜡产品市场供需现状分析

蜡类产品的应用非常广泛,在许多家庭用品和工业用品中都能经常遇到.石油蜡仍是目前蜡市场的主流产品,但使用量在逐年降低.中国是全球最大的石油蜡生产国,全球大约有1/3的石油蜡都产自中国.聚烯烃蜡在美国和欧洲市场的应用发展更为迅速,具有更好的市场前景,值得关注.     

我国汽车用蜡的现状与发展建议

对我国汽车用蜡的现状和发展作了介绍。同时提出发展我国汽车用蜡应当尽早开展专题研究,以轿车用蜡为突破口,开发汽车用蜡系列产品。加强机理和工艺等方面的研究,以解决目前产品存在的质量问题,提高产品的市场竞争力。     

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.     

Analytical characterisation and production of wool wax from Akkaraman and Morkaraman sheep's wool

The analytical characterisation and production of wool wax from Akkaraman and Morkaraman sheep in the East Anatolien region of Turkey have been investigated. It was shown that the analytical characteristics of Akkaraman and Morkaraman wool waxes differ only slightly from other wool waxes. Therefore, from a quality point of view, wool waxes obtained from this work can be used for the same purposes as wool waxes produced from different varieties of sheep.