共查询到20条相似文献,搜索用时 125 毫秒
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吴国江 《精细与专用化学品》2011,19(12):18-21
研究了用58#全炼蜡、巴西棕榈蜡、改性聚乙烯蜡、硅油等制备汽车上光乳化蜡的方法。考查了石蜡、巴西棕榈蜡、改性聚乙烯蜡三者的比例、硅油类型、乳化剂类型、摩擦剂用量对乳液性能的影响。实验结果表明,当乳化剂用量为乳液质量的10%,乳化温度为90±3℃,乳化时间为50min,可以制取一种达到国外同类产品水平的汽车上光乳化蜡。 相似文献
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介绍我国汽车用橡胶软管的市场需求和生产状况,概述国外汽车用橡胶软管的现状及发展动向,分析我国汽车用橡胶软管的发展趋势及其与国外产品的差距,对我国汽车用橡胶软管的发展提出建议。 相似文献
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多功能、高附加值乳化蜡产品的生产及应用 总被引:15,自引:0,他引:15
介绍了国内外乳化蜡产品的发展和应用状况,分析了国内生产乳化蜡产品的优越性、经济性及潜在的市场情况。对我国乳化蜡产品的研究和开发提出了建议 相似文献
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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. 相似文献
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B. Müller 《European Journal of Lipid Science and Technology》1967,69(8):589-592
The influence of Waxes on the Properties of Printing Inks The influence of waxes on the properties of printing inks and printed materials is shown with the examples of straight chain and differently branched hydrocarbons. The waxes in finely dispersed state are imbedded in the printing inks like pigments and retain this state in the dried printing ink film. Polyethylene waxes change the rheological behaviour of the printing inks and above all improve the scratch and scrubb resistance of the finished prints. On the basis of measurements carried out with printing inks and printed matter it has been tried to explain the mechanism of the action of polyethylene waxes on the printing inks. 相似文献
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E. Finck 《European Journal of Lipid Science and Technology》1967,69(1):8-13
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. 相似文献
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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. 相似文献
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Benjamin Gosney Julianne O’Reilly-Wapstra Lynne Forster Carmen Whiteley Brad Potts 《Journal of chemical ecology》2017,43(5):532-542
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. 相似文献
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Jürgen Jacob 《Lipids》1978,13(4):274-282
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. 相似文献
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- The potentiometric titration method is superior to color-indicator methods in the determination of acid and saponification values of earth waxes.
- The saponification reaction in determining saponification values of earth waxes is a balanced one; therefore the equilibrium depends on conditions under which it is run.
- Hydroxyl and carbonyl value methods have been modified to make them suitable for earth (mineral) waxes.
- The values obtained on high-molecular weight peat waxes are not absolute, but rather they serve to characterize and identify these products.
- The methods explained in this report may perhaps be found suitable for other natural products, such as montan wax.
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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. 相似文献
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Quantitative analyses on the coefficient of friction of common coating waxes are necessary and essential for designing systems for coating, conveying, packaging operations, transporting, and storing of papers and paperboards, while analyses on wear behavior can be helpful for predicting performance durability of the coating surface. In this study, we investigated the friction and wear behaviors of six waxes including four commercial waxes and two soybean oil-based wax developed in our lab for bulk corrugated coating. The effect of normal load, sliding velocity, and environmental temperature was evaluated. The friction coefficient of different waxes varies with sliding conditions. Higher normal load, sliding velocity, and environmental temperature resulted in significantly greater wear loss. Crystalline morphology and crystallinity of waxes were affected by the environmental temperature, and they correlate to the variations in friction coefficient and wear loss of these materials. 相似文献
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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. 相似文献