Functionalization at the double-bond region of jojoba oil. 8. Chemical binding of jojoba liquid wax to a polymer matrixvia an amine “spacer”

Jojoba wax was chemically bonded to a polymer matrixvia stable C-N covalent bonds. The polymer matrix was prepared by amination of several types of styrene-divinyl benzene or styrene-vinylbenzylchloride-divinylbenzene copolymers with diamines or polyethylene imines (polyamines). The jojoba wax was attached to the aminated polystyrene matrix by reacting an allyl-brominated derivative of jojoba with the matrix to form a C-N bond between the matrix and the jojoba wax. The amount of bound jojoba wax added to the polymer was in the range of 20–70% (w/w), depending on the type of polymer matrix and reaction conditions. The double-bond regions in the jojoba wax bonded to the matrix were preserved, and they were subsequently functionalized by phosphonation and sulfur-chlorination reactions.     

Application of jojoba wax bound to polyethylene membranes and hollow fibers in ion‐exchange and pervaporation processes

Chlorosulfonated polyethylene membranes and hollow fibers were reacted with allylic amino jojoba to bind the wax chemically to the polymer. The modified membranes and hollow fibers were then tested in the ion‐exchange and pervaporation processes, respectively. The jojoba‐bound polyethylene membranes were selective in preventing transfer of divalent ions such as Ca²⁺ and Mg²⁺, while monovalent ion such as K⁺ and Na⁺ could penetrate the membranes. The flux of the monovalent ions depended on the amount of jojoba bound to the polymer, which acted as a barrier to the ions (the monovalent ions could be eluted by acid washing). The concentration of ions (in the range of 0.05–1.0 N) in the feed solution had little effect on the flux. Preliminary results of pervaporation of a dioxane/water mixture through hollow fibers made of jojoba‐bound chlorosulfonated polyethylene show separation of the dioxane from the water with a separation factor of 6. This technique can be applied to remove residual organic solvents in the purification of industrial waste water. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 763–768, 2001     

Functionalization at the double-bond region of jojoba oil. 7. Chemical binding of jojoba liquid wax to polystyrene resins

Jojoba wax was chemically bonded to a polystyrene matrixvia a stable C-C covalent bond. This was achieved by binding allyl-brominated jojoba derivatives to lithiated crosslinked polystyrene-2% divinylbenzene or XAD-4 polymeric beads via a nucleophilic substitution reaction. The double-bond regions in the jojoba wax were preserved. A side reaction that accompanied the nucleophilic substitution was HBr elimination, which produced diene and triene systems in the bound jojoba. Phosphonation and sulfur chlorination at the double bonds of the jojoba wax, bonded to the polystyrene matrix, were also performed.     

Functionalization at the double-bond region of jojoba oil. 9. solid-state nuclear magnetic resonance characterization of substituted jojoba wax chemically bonded to a polystyrene matrix

Solid extractants for metal ions have been prepared by chemical bonding of jojoba wax to a polystyrene backbone, followed by phosphonation or sulfur-chlorination of the jojoba moiety. In this study, the intermediates and final solid products of the reactions were characterized by solid-state ¹³C and ³¹P nuclear magnetic resonance spectroscopy. The spectra showed the expected chemical shifts of the atoms involved in the chemical reactions, as well as other parts of the reacting molecules. Thus, the carbonyl carbon of the jojoba chain appears at 175 ppm, the methyl carbons at 15 ppm, the polystyrene backbone at 40–42 ppm (aliphatic carbons) and 128, 137, 143–147 (aromatic carbons). Carbons adjacent to N, S, and P appear at 45–55, 60, and 48 ppm, respectively.     

Retardation effect of jojoba chain length on the chemical reactivity of the liquid wax

Jojoba wax and its derivatives are slow-reacting compounds. To elucidate the reasons for this phenomenon, we reacted jojoba mono- and bis-epoxide and trans-jojoba bis-epoxide (C₃₈–C₄₄ long-chain esters), as well as side chain esters of three steroid skeleton mono-epoxide derivatives with NaI under acidic conditions to yield the corresponding iodohydrins, which then formed the respective bis-keto (or mono-ketone) derivatives. The kinetics, activation energies, and thermodynamic parameters of activation of nucleophilic epoxide opening and pinacol rearrangement were determined for all these compounds. The reaction rates of the jojoba derivatives were similar to those of two of the epoxides derived from the steroid skeleton compounds, and in the third case the steroid derivative reacted somewhat faster than all the rest. This pattern of rate retardation could stem either from folding of the long jojoba chain, resulting in steric hindrance around the reaction centers, or from repeated unproductive collisions along the long hydrocarbon chain of the jojoba wax (statistical effect). Our results appear to suggest that the multiple unsuccessful collisions were the dominant factor, although steric hindrance cannot be ruled out.     

Differential scanning calorimetry index for estimating level of saturation in transesterified wax esters

Differential scanning calorimetry (DSC) thermograms of fatty esters can give valuable information on melting characteristics and heats-of-fusion enthalpy (ΔH). A series of jojoba liquid wax esters was constructed by transesterifying native jojoba oil with 5–50% completely hydrogenated jojoba wax esters. This series, when subjected to a standardized DSC tempering method with heating/cooling cycles, exhibited an excellent correlation for level of saturation based on area changes in endothermic ΔH. Endothermic events were recorded for native (ΔH_A) and completely hydrogenated (ΔH_C) jojoba wax esters. A third endotherm, ΔH_B, was observed when they were transesterified. Based on a multiple regression program, the best fit (R²=0.98) using ΔH data was: % saturation=16.847–0.162 (ΔH_A)+0.209 (ΔH_B)+0.600 (ΔH_C). Standard errors for predictions were approximately 1.045 at 0% saturation, 0.770 at 25% saturation, and 1.158 at 50% saturation. Endothermic events A, B, and C each represent the respective diunsaturated, mounounsaturated, and saturated contents of wax esters in the transesterified blends. This was verified by measuring the dropping points for both the native and completely hydrogenated wax esters. These findings provide an index which can predict the degree of saturation in transesterified wax ester blends and serves as a research tool in process and product developments. Presented at the 1995 AOCS Meeting, May 7–11, 1995, San Antonio, Texas. Retired.     

Effect of the extraction and bleaching processes on jojoba (Simmondsia chinensis) wax quality

The aim of the work was to evaluate the effect of extraction method and bleaching on the quality of jojoba waxes from Argentina. Jojoba waxes obtained by cold pressing, Golden wax (expeller‐pressed wax) and Lite wax (bleached wax) were analyzed using standard methods adopted as recommended practices by the American Oil Chemists Society. Physical parameters, fatty acid and alcohol compositions were unchanged among waxes. Cold‐pressed wax was noteworthy by its lower peroxide value, higher amounts of tocopherol and total phenol contents. Accordingly, it presented the best oxidative stability. Bleaching caused a strong decrease in both tocopherol and phenol contents; consequently the bleached wax showed poor oxidative stability.     

Effect of female and male genotypes and environment on wax composition in jojoba

The objective of this study was to determine the effects of genotype and environment on wax composition in jojoba seed, and thus be able to control it. Production of waxes with different compositions—and hence changed wax properties such as viscosity, boiling point, and thermal stability—may be of importance for future requirements of the jojoba industry. Wax composition of 23 female clones was determined for two growing seasons. The ratio of FA elongated to the sum of those reduced and esterified differed among genotypes, resulting in differences in the percentage of wax esters longer than 40 or 42 carbons. The clones ‘Yarden,’ ‘Gvati’, ‘Hazerim,’ ‘BGU,’ and ‘Negev’ had higher percentages of long-chain wax moieties than the clones ‘879–154’, ‘MS 55–4’, and ‘Forti.’ The contribution of the male genotype to wax composition was tested by pollinating bagged female flowers of four female clones with pollen from three male plants. Both male and female genotypes additively influenced the composition of the wax esters. Wax composition varied between growing seasons and locations, but differences between genotypes were consistent. Salinity of the irrigation water did affect wax composition in some clones. Under high salinity, the salt-sensitive clone ‘64’ produced a smaller percentage of long-chain wax esters, whereas in clone ‘Q-106’ wax composition did not change. In clone ‘874–154’ the chain lengths of the wax moieties in the seeds increased under medium salinity. We conclude that jojoba wax composition is influenced by both female and male genotypes and by environmental factors such as climate and salinity.     

Jojoba oil analysis by high pressure liquid chromatography and gas chromatography/mass spectrometry

Two analytical procedures for determining com-positions of jojoba liquid wax esters are described and compared. One, the more tedious, involves separation of wax ester homologs by high pressure liquid chro-matography followed by determination of the acid and alcohol moieties from each homolog. The second allows rapid determination of wax ester composition by gas Chromatographic separation of hydrogenated jojoba wax esters according to chain length, followed immediately by ancillary mass spectrometric identifi-cation of the acid and alcohol moieties. Double bonds in the alkyl chains in jojoba liquid waxes were almost exclusively (98%) ω-9, when examined by gas chro-matography/mass spectrometry (GC/MS) and ozonolysis/GC/MS. Presented in part at the 2nd International Conference on Jojoba and Its Uses, Ensenada, Mexico, February, 1976.     

Functionalization at the double bond region of jojoba oil. 6. Production of aminesvia azides

The apolar and hydrophobic jojoba molecule was made more hydrophilic by the incorporation of primary amino groupsvia the introduction and subsequent reduction of azido groups. The azides were obtained by the substitution of bromine or a mesylate group introduced into the jojoba oil molecule; by opening of the epoxide ring in epoxy jojoba; or by the addition of bromoazide to the double bonds of jojoba.     

Synthesis of oleyl oleate as a jojoba oil analog

Synthesis of a wax ester analog of jojoba oil was accomplished from oleic acid and oleyl alcohol with a zeolite as catalyst. A full 2³ factorial design at two levels has been used in the synthesis. The variables selected were temperature, reduced pressure and initial catalyst concentration. The most important variable within the range studied was temperature. Reduced pressure had a negative influence, and initial catalyst concentration showed a positive influence on the process. A response equation has been determined for the yield of ester. The properties of the synthesized product are similar to those of natural jojoba oil.     

Hydroxymethylation of jojoba oil by lewis acid-catalyzed ene reaction with formaldehyde

Formaldehyde undergoes ethylaluminum dichloride-catalyzed ene reaction with jojoba oil to afford a mixture of 1∶1 and 1∶2 adducts. The hydroxymethyl products were identified by comparison with model adducts prepared from methyl oleate and oleyl acetate.     

Jojoba wax: Its esters and some of its minor components

A lack of reliability in the usual determinations of fatty acids and fatty alcohols of jojoba wax prompted us to propose an original method of hydrolysis and extraction, making it possible to better determine the composition of fatty acids and alcohols of the wax. High-performance liquid chromatography fractionation of the wax allowed isolation of four main classes of esters (which differed by their partition number). The detailed study of these ester classes emphasized the way acids and alcohols are connected, and fourteen distinct esters were thus identified. Some triacylglycerols, free fatty alcohols and other minor components of jojoba wax were found and quantitated. Seven sterols were identified, four for the first time.     

Oxidative stability of jojoba wax

The rates of autoxidation of crude, bleached and stripped jojoba wax were determined under conditions of accelerated oxidation (98 C). Oxidation of the raw yellow wax had a long induction period (50 hr) compared with the bleached wax (10–12 hr) or stripped wax (2 hr). These differences indicate the presence of a natural antioxidant in the crude wax. Addition of 0.02% butylated hydroxytoluene or butylated hydroxyanisole to the bleached wax restored and even improved its stability. Autoxidation of jojoba wax was also studied at room temperature. In the presence of light and air, the activity of the natural inhibitor was rapidly lost.     

Absorption and distribution of jojoba wax injected subcutaneously into mice

¹⁴C-Labeled jojoba wax was injected subcutaneously into mice and¹⁴C was determined 1–90 days after application in several internal organs, in the skin and in the lipids extracted from the carcass. A control group of mice was similarly treated with triolein. The major part of the injected lipids was not absorbed or metabolized. Some label was found in the organs examined, but there was no accumulation of labeled lipids with time. About 20% of label derived from triolein was found in polar lipids, whereas only 2–4% of that derived from jojoba wax was found in this fraction. There was some (1–5%) incorporation of the label of jojoba wax into body triglycerides.     

废旧聚乙烯催化降解制备聚乙烯蜡

以废旧聚乙烯为原料,Al-MCM-48为催化剂,在高压釜内催化裂解制备聚乙烯蜡。用红外光谱对产品进行了分析,讨论了催化剂、反应温度和时间对产品的影响。实验结果表明:裂解的适宜加工条件为,催化剂含量0.3%,反应温度360~380℃,反应时间4h。在适宜的加工条件下,所得聚乙烯蜡产品为黄色,分子量在1300~1800之间滴,熔点约为106℃,针入度约为0.17mm。     

X-ray study of hydrogenated jojoba wax

Crystallographic analysis of hydrogenated jojoba wax ester shows the crystal structure to be monoclinic with orthorhombic perpendicular, 0⊥, chain packing. Cell dimensions are: a=4.99, b=7.44, c=55.2Å, β=90°. A larger secondary unit cell is observed and identified as permitting the hydrocarbon ester chains freedom of rotation. Hydrogenated jojoba was ester is crystallographically similar to polyethylene.     

Co-crystals of Beeswax and Various Vegetable Waxes with Sterols Studied by X-ray Diffraction and Differential Scanning Calorimetry

In this study, mixtures of purified wax and sterols were melted and subsequently cooled. Using X-ray diffraction of the mixed, solid phase, it was shown that for up to 30–40 wt% sterols no measurable re-crystallisation of sterols occurred, i.e. the sterols became dissolved at a molecular level. Probably a form of amorphous co-crystals of sterols and wax is formed if the molecular ratio does not exceed 1:1. Differential scanning calorimetry (DSC) suggests that a minor amount of pure sterols could already be present at lower sterol levels. This may be because of the higher temperature at which the microstructure is probed when using DSC—melting of the wax might lead to crystallisation of the sterols. For application in foods, the structure as probed by X-rays at ambient temperatures is more relevant. When sunflower wax and rice bran wax are used, prevention of sterol crystallisation is even more pronounced, probably because the melting temperatures of these waxes are closer to the melting temperature of sterol crystals. Replacing the beeswax with a saturated fat (heRP70), sunflower oil, or jojoba wax (a liquid wax) substantially increases the amount of crystalline sterols. The difference between the various waxes and fats was qualitatively the same for X-ray diffraction and DSC. Stanols can be incorporated in the same manner and up to similar concentrations. Another insoluble nutritional compound, ursolic acid, has a greater tendency to crystallise in wax. This is probably because the melting temperature of ursolic acid is much higher than that of wax.     

聚乙烯副产物中稀释剂和聚乙烯蜡的提取

以辽阳石油化学纤维公司化工三厂高密度聚乙烯副产原料，采用水蒸汽蒸馏的方法，分离得到稀释剂和低分子量聚乙烯。讨论了各种工艺条件变化对蒸馏质量的影响。确定了分离的最佳工艺条件。     

一种汽车上光乳化蜡的研制

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。