Combustion characteristics of candles made from hydrogenated soybean oil

Hydrogenated soybean oil, referred to as soywax by candle makers, is a renewable and biodegradable alternative to paraffin wax in candle manufacturing. Soywax was investigated for its tendency to produce soot as well as potentially harmful organic volatiles (acrolein, formaldehyde, and acetaldehyde) during combustion. Beeswax and paraffin candles were used as references. A considerable amount of soot was produced from the combustion of paraffin candles, but little or none was observed from soywax candles. Compared to paraffin candles, soywax candles burned at a significantly slower rate and required less air. Small amounts of formaldehyde were detected and quantified in the fumes of burning paraffin candles. However, formaldehyde, peaks found in the chromatograms of soy- and beeswax candles were similar to or slightly higher than that of the blank. Since soywax candles exhibited burning properties similar to those of beeswax candles, soywax shows promise in candle applications.     

Chemical Modification of Partially Hydrogenated Vegetable Oil to Improve its Functional Properties for Candles

Partially hydrogenated vegetable oil (PHVO) has recently been used to make vegetable oil-based candles. However, its use is limited primarily to container candles because of its inherent physical properties, such as brittleness when a hard material is produced, and greasiness when it is soft by low degree of hydrogenation. Such material lacks the most desired cohesiveness and elasticity compared to the commercial petroleum paraffin and beeswax. To improve the cohesiveness and thermal properties of PHVO, epoxidation, ring-opening reaction, and esterification were conducted to introduce new functional groups into the fatty acyl chain of PHVO. These newly synthesized derivatives or waxes were also mixed with the fully hydrogenated soybean oil (FHSO) or PHVO base materials. Hardness and cohesiveness of the new waxes and the mixtures were measured with a texture analyzer. Their thermal properties were analyzed with a differential scanning calorimetry (DSC). It was found that the introduction of hydroxyl (OH) group significantly improved the cohesiveness of PHVO. The melting range of PHVO also increased after the reactions. However, the hardness of the new wax was lower than those of commercial paraffin wax or beeswax. For wax mixtures, the hardness of dihydroxy wax was significantly improved by the addition of FHSO, however, the cohesiveness was negatively affected by the amount of FHSO added. Both the melting and the crystallization ranges were widened by mixing the derivatives with the base materials.     

Waxes in the candle industry

Summary 1. The waxes in use for candles consist of paraffin and, in special cases, of beeswax. 2. Stearic acid is the only known hardening agent for paraffin. It raises the bending (softening) point and lowers the melting point. It can be used in any quantity without impairing the burning quality of the candle. 3. No other wax, natural or synthetic, can be substituted for stearic acid as a hardening agent for candle stock. Other waxes generally injure the burning quality of the candle or fail to produce any improvement, being at the same time more expensive than stearic acid. 4. The hydrogenated oils and fats serve as hardening agents for paraffin, especially for scale paraffin wax, and are used chiefly for candles which are consumed in glasses. 5. Synthetic or natural resins can be used in form of coatings only and are used chiefly for decorative candles. 6. No known synthetic hardening agent for candle wax can be satis-factorily substituted for stearic acid, even in such a mixture as 95% paraffin (MP 135°) and 5% stearic acid.     

Synthesis and Characterization of Acetylated and Stearylyzed Soy Wax

A solvent-free synthesis method was developed for incorporating acetyl and hydroxy groups and long-chain fatty alcohol in fully hydrogenated soybean oil (FHSO) to produce a wax to be used as beeswax or paraffin substitutes in packaging and coatings. FHSO was reacted with stearyl alcohol and triacetin at 140–150 °C for 2 h, and the reaction was catalyzed by 0.018 wt% sodium methoxide. The addition of alcohol increased the reaction yield and the melting point of the final wax by 9 and 25 %, respectively, compared to the wax produced from the reaction of FHSO and triacetin alone. The effects of the ratio of stearyl alcohol and triacetin to FHSO on the textural properties of the modified soy wax were examined. The reaction of FHSO:stearyl alcohol:triacetin at a molar ratio of 9:7:15 produced a wax that was 1.2 and 2.4 times harder than beeswax and FHSO, respectively, but 1.7 times softer than a commercial grade paraffin wax. This modified soy wax comprised 75 % acetylated glycerol esters including diacetylmonoacylglycerides (31 %), monoacetylmono- (12 %) and diacylglycerides (32 %), and 25 % non-acetylated molecules including wax ester (14 %), and acylglycerides (11 %). The acetylated soy wax had high cohesiveness and did not break under compression.     

Synthesis of Functionalized High‐Oleic Soybean Oil Wax Coatings and Emulsions for Postharvest Treatment of Fresh Citrus Fruit

High‐oleic soybean oil is chemically functionalized in order to mimic the structure and physical properties of hydrogenated castor oil (HCO). The resulting wax‐like material is evaluated for use as an alternative to other commercial wax coatings for the postharvest treatment of fresh citrus fruit. The racemic nature of the material inhibits ordered crystalline arrangement and negatively affects its relative crystallinity (17.7%), hardness (0.59 ± 0.04 mm^?1), and melting profile (44–46 °C), with respect to HCO oil (37.7%, 5.33 ± 0.01 mm^?1, 83–87 °C). Nevertheless, compounding the new material with carnauba wax (CAR) imparts a very attractive gloss and prevents moisture loss significantly better than polyethylene, shellac, and CAR‐based coatings. Compounding the hydroxy‐functionalized high‐oleic soybean wax may potentially reduce dependence on imported CAR and other ingredients used in citrus coating emulsion formulations. Practical Applications: The soybean oil‐derived material described in this contribution provides two key performance characteristics desired by citrus growers and packing houses: an efficient barrier to moisture loss and an attractive shine. The synthesis of the hydroxy‐wax is facile and mild, and the materials can be readily formulated into emulsions as required for fruit coating applications. Use of the formulated coating can be extended to other agricultural commodities such as avocados, melons, and stone fruit.     

Margarine from Organogels of Plant Wax and Soybean Oil

Organogels obtained from plant wax and soybean oil were tested for their suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showed relatively good firmness with the organogel, but dramatically lowered firmness for a margarine sample. Sunflower wax showed the greatest firmness for organogel and the margarine samples among the three plant waxes tested in this study. Firmness of the margarine containing 2–6 % sunflower wax in soybean oil was similar to that of margarine containing 18–30 % hydrogenated soybean oil in soybean oil. The firmness of commercial spread could be achieved with about 2 % sunflower wax and that of commercial margarine could be achieved with about 10 % of sunflower wax in the margarine formulation. Dropping point, DSC and solid fat content of the new margarine containing 2–6 % sunflower wax showed a higher melting point than commercial margarine and spreads.     

Blending of hydrogenated low-erucic acid rapeseed oil,low-erucic acid rapeseed oil,and hydrogenated palm oil or palm oil in the preparation of shortenings

Two ternary systems of fats were studied. In the first system, low-erucic acid rapeseed oil (LERO), hydrogenated lowerucic acid rapeseed oil (HLERO), and palm oil (PO) were blended. In the second system, hydrogenated palm oil (HPO) was used instead of PO and was blended with LERO and HLERO. The blends were then studied for their physical properties such as solid fat content (SFC), melting curves by DSC, and polymorphism (X-ray). HPO showed the highest melting enthalpy after 48 h at 15°C (141±1 J/g), followed by HLERO (131±2 J/g), PO (110±2 J/g), and LERO (65±4 J/g). Binary phase behavior diagrams were constructed from the DSC and X-ray results. Iso-line diagrams of partial-melting enthalpies were constructed from the DSC results, and binary and ternary isosolid diagrams were constructed from the NMR results. The isosolid diagrams demonstrated formation of a eutectic along the binary blend of PO/HLERO. However, no eutectic effect was observed along the binary lines of HPO/HLERO, PO/LERO, HPO/LERO, or HLERO/LERO. The same results were found with the iso-line diagrams of partial-melting enthalpies. As expected, addition of PO or HPO increased polymorphic stability in the β′ form of the HLERO/LERO mixture.     

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.     

复合添加剂对石蜡性能影响的研究

以聚乙烯蜡和硬脂酸为添加剂,采用水浴加热混合蜡测量滴熔点和粘度,在聚乙烯蜡质量百分含量为0％ ～ 15％、硬脂酸质量百分含量为0％ ～ 60％范围内,对石蜡的使用性能进行改性研究.实验结果表明,聚乙烯蜡和硬脂酸均对石蜡滴熔点和运动粘度有一定的影响.在聚乙烯蜡添加量为0％ ～ 15％的范围内,改性石蜡的性能得到明显改善,其中改性石蜡的滴熔点呈缓慢增高趋势,后保持稳定;当其添加量在3％～5％的范围内,改性石蜡的熔点快速升高.在聚乙烯蜡加入量为3％时加入质量分数为5％～60％硬脂酸进行对比试验.硬脂酸在添加量为5％～25％时,改性石蜡滴熔点呈下降趋势;硬脂酸添加量为25％～60％时,改性石蜡滴熔点上升,但上升效果不明显.     

Candle-based process for creating a stable superhydrophobic surface

A superhydrophobic surface with stability against moderate drop impact was quickly created with only a candle. There was no further need for any additional solvent, further surface treatment, drying process or post-treatment process. The fabrication is very simple. A surface is coated with a candle paraffin wax and then sooted with a candle flame. The paraffin wax was used to fix the fragile candle soot. This paraffin wax-fixed candle soot (PFCS) coating showed improved drop impact durability by up to a factor of 50, compared to a bare soot coating without a paraffin wax treatment. Thermal stability, compression tolerance, and pH tolerance of the PFCS coating were tested. The mechanism behind the PFCS coating and durability enhancement of the coating is explained. The simple PFCS coating method can be applied to various surfaces, such as metal, ceramic, wood, plastic and even paper. We provide proof-of-concept demonstrations in the application of this PFCS coating method. We foresee PFCS coating as opening up a new avenue for the development of an inexpensive and quick process for the fabrication of superhydrophobic surfaces.     

高孔隙率泡沫铜强化相变材料熔化特性

为了研究纯石蜡与泡沫铜/石蜡相变复合材料吸热熔化性能的不同,探究泡沫铜对石蜡熔化换热过程的影响,本文对纯石蜡和孔隙率为0.98的高孔隙率泡沫铜/石蜡复合材料的相变熔化过程进行了可视化实验研究,并数值模拟分析了纯石蜡及泡沫铜/石蜡复合材料熔化过程。结果表明：复合材料与纯石蜡的液相率变化出现交点,即临界液相率值,此时复合材料具有的液相占比与纯石蜡液相占比相同;泡沫铜的填充能明显改善纯石蜡传热系数低的问题,加快相变材料的整体熔化速率,当热通量为1200W/m2时,孔隙率为0.98的泡沫铜填充使纯石蜡完全熔化时间缩短了约12.5%,并使整体温度分布更均匀,改善热分层现象,且复合材料最大温差比纯石蜡最大温差低约27.5K。     

A New Benzylated Fatty Acid Amide Amphoteric Surfactant Derived from Hydrogenated Castor Oil with Ultra-Low Interfacial Tension between Crude Oil and Brine

Hydrogenated castor oil from castor oil is promisingly used as raw materials for lubricants, coatings, cosmetics, and pharmaceutics due to high melting point and stable physical properties. However, the chemical modification of the hydrogenated castor oil has been rarely investigated. Here, we report a N-phenyl-fatty-amido-1-propyl-N,N-dimethyl-amino-carboxyl-betaine surfactant derived from hydrogenated castor oil with excellent interfacial properties through a rapid synthetic process, including direct alkylation, amidation, and quaternization. The interfacial tension between crude oil and brine was ultra-low for a low dosage of 0.007 g L⁻¹ of surfactant in aqueous solution without any alkali addition, which implies a potential application in enhanced oil recovery.     

A modified method for determining free fatty acids from small soybean oil sample sizes

A modification of the AOCS Official Method Ca 5a-40 for determination of free fatty acids (FFA) in 0.3 to 6.0-g samples of refined and crude soybean oil is described. The modified method uses only about 10% of the weight of oil sample, alcohol volume, and alkali strength recommended in the Official Method. Standard solutions of refined and crude soybean oil with FFA concentrations between 0.01 and 75% were prepared by adding known weights of oleic acid. The FFA concentrations, determined from small sample sizes with the modified method, were compared with FFA percentages determined from larger sample sizes with the Official Method. Relationships among determinations obtained by the modified and official methods, for both refined and crude oils, were described by linear functions. The relationship for refined soybean oil had an R ² value of 0.997 and a slope of 0.99±0.031. The values for crude soybean oil are defined by a line with R ²=0.9996 and a slope of 1.01±0.013.     

A油田油井结蜡机理及清防蜡对策研究

针对A油田油井全井段结蜡的特殊性,从影响结蜡的主要因素入手,分析了原油组分、原油含蜡量,蜡样成分;同时考虑压力与气油比对析蜡温度的影响,采用高温高压釜与石蜡沉积激光检测仪分析了不同压力、不同气油比下析蜡点,掌握了A油田全井段结蜡的主要原因,得出了原油析出蜡主要以微晶蜡为主,而且熔点较高,不宜采用热洗方法清蜡。针对这一点,现场开展了防蜡防垢降粘增油器、声波防蜡器、空化防蜡器三种防蜡工艺对比试验;室内评价了长庆油田目前在用的五种清蜡剂对A油田的适应性。优选出适合A油田的防蜡工具和化学清蜡剂,对该油田清防蜡工作的开展有一定的技术指导意义。     

Trans‐free fats through interesterification of canola oil/palm olein or fully hydrogenated soybean oil blends

Binary blends of canola oil (CO) and palm olein (POo) or fully hydrogenated soybean oil (FHSBO) were interesterified using commercial lipase, Lypozyme TL IM, or sodium methoxide. Free fatty acids (FFA) and soap content increased and peroxide value (PV) decreased after enzymatic or chemical interesterification. No difference was observed between the PV of enzymatically and chemically interesterified blends. Enzymatically interesterified fats contained higher FFA and lower soap content than chemically prepared fats. Slip melting point (SMP) and solid‐fat content (SFC) of CO and POo blends increased, whereas those of CO and FHSBO blends decreased after chemical or enzymatic interesterification. Enzymatically interesterified CO and POo blends had lower SMP and SFC (at some temperatures) than chemically interesterified blends. The status was reverse when comparing chemically and enzymatically interesterified CO and FHSBO blends. The induction period for oxidation at 120°C of blends decreased after interesterification. However, chemically interesterified blends were more oxidatively stable than enzymatically interesterified blends. Interesterified blends of CO and POo or FHSBO displayed characteristics suited to application as trans‐free soft tub, stick, roll‐in and baker's margarine, cake shortening and vanaspati fat.     

Soy hull as an adsorbent source in processing soy oil

Soy hull, a co-product of the soybean industry, was evaluated as an adsorbent source for processing soy oil. Ground soy hull (<100 mesh), boiled soy hull, and soy hull carbon were each added to crude soy oil at various levels in the laboratory under commercial bleaching conditions. The free fatty acid (FFA), peroxide value (PV), pigments, and total phospholipid contents (PL) of treated samples were measured. The microstructure (scanning electron microscopy, SEM), X-ray diffraction patterns (XRD), and Fourier transform infrared (FTIR) spectra of the soy hull adsorbents were also examined. The soy hull carbon was more efficient as an adsorbent relative to the ground or boiled soy hulls. The differences between ground and boiled soy hulls in the reduction of FFA were not significant. The effectiveness of adsorbents to reduce PV was: soy hull carbon > boiled soy hull = untreated soy hull; and for PL adsorption: soy hull carbon = ground soy hull > boiled soy hull. Boiling resulted in an open, porous structure, as evident from the SEM data, but carbonization did not affect the particle size. The XRD patterns of ground and boiled soy hulls were similar to those of powdered amorphous cellulose, but the carbon was more amorphous and had a random structure, as well as a more polar surface, as revealed by the FTIR spectra.     

Fatty acids,fatty alcohols,and wax esters fromLimnanthes douglassi (Meadowfoam) seed oil

Limanathes douglasii seed oil glycerides contain fatty acids which predominantly (97%) have 20 or more carbon atoms. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of the glycerides; and liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of the fatty acids with the fatty alcohols. Solid waxes were prepared by hydrogenation of the glyceride oil and of the wax esters. Chemical and physical constants were determined forLimnanthes douglasii seed oil and its derivatives. The liquid wax esters had properties very similar to those of jojoba (Simmondsia chinensis) seed oil. The solid hydrogenated wax ester was identical in physical appearance and melting point to hydrogenated jojoba seed oil. A laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, USDA.     

Properties of Oleogels Formed With High‐Stearic Soybean Oils and Sunflower Wax

In an effort to develop alternatives for harmful trans fats produced by partial hydrogenation of vegetable oils, oleogels of high‐stearic soybean (A6 and MM106) oils were prepared with sunflower wax (SW) as the oleogelator. Oleogels of high‐stearic oils did not have greater firmness when compared to regular soybean oil (SBO) at room temperature. However, the firmness of high‐stearic oil oleogels at 4 °C sharply increased due to the high content of stearic acid. High‐stearic acid SBO had more polar compounds than the regular SBO. Polar compounds in oil inversely affected the firmness of oleogels. Differential scanning calorimetry showed that wax crystals facilitated nucleation of solid fats of high‐stearic oils during cooling. Polar compounds did not affect the melting and crystallization behavior of wax. Solid fat content (SFC) showed that polar compounds in oil and wax interfered with crystallization of solid fats. Linear viscoelastic properties of 7% SW oleogels of three oils reflected well the SFC values while they did not correlate well with the firmness of oleogels. Phase‐contrast microscopy showed that the wax crystal morphology was slightly influenced by solid fats in the high‐steric SBO, A6.     

Investigation into Paraffin Wax and Ethylene Vinyl Acetate Blends for Use as a Carrier Vehicle in Ceramic Injection Molding

An experimental study into paraffin wax and ethylene vinyl acetate-28 blends has been undertaken to investigate the potential for their use as carrier vehicles for ceramic injection molding applications. Carrier systems are critical for the fabrication of this type of molded component, making their properties at all stages of the process of great importance. Paraffin wax and ethylene vinyl acetate-28, in most circumstances, combine to form stable homogeneous blends, which experience relatively small changes in the melting and solidification phase transition behavior. However, these blends exhibit notable viscosity shifts and flexural strength performance changes with increasing ethylene vinyl acetate-28 content. The melt flow behavior of the blends at shear rates of 100 s^?1 varies from 0.01 Pa.s for paraffin wax to 10 Pa.s for the composition by weight of 50% paraffin wax and 50% ethylene vinyl acetate-28, which suggests the upper viscosity limit for successful carrier systems. All paraffin wax/ethylene vinyl acetate-28 blends experience shear thinning behavior with increasing shear rate, which can be modeled with reasonable accuracy using the Cross and Carreau models. Increasing the ethylene vinyl acetate-28 content in a blend causes the initiation of shear thinning at progressively lower shear rates and also forms a blend with an increasing elastic character at typical injection temperature. Yield stress is not developed for blends containing less than 50 wt% ethylene vinyl acetate-28. The addition of ethylene vinyl acetate-28 significantly alters the mechanical properties of the blends, modifying the brittle nature of paraffin wax to develop increasing flexible and plastic properties. Although with less than 25 wt% ethylene vinyl acetate-28 in a blend fracture failure still results, greater ethylene vinyl acetate-28 content represses the failure mechanisms, developing the increasing degrees of plastic deformation.     

Polymorphic behavior of some fully hydrogenated oils and their mixtures with liquid oil

Fully hydrogenated soybean oil, beef fat, rapeseed oil, a rapeseed, palm and soybean oil blend, cottonseed oil and palm oil were characterized by fatty acid composition, glyceride carbon number and partial glyceride content, as well as melting and crystallization properties. The latter were established by differential scanning calorimetry. Polymorphic behavior was analyzed by X-ray diffraction of the products in the flake or granulated form and when freshly crystallized from a melt. The hard fats were dissolved in canola oil at levels of 20, 50 and 80% and crystallized from the melt. Palm oil had the lowest crystallization temperature and the lowest melting temperature; rapessed had the highest crystallization temperature and soybean the highest melting temperature. All of the hard fats crystallized initially in the =00 form. When diluted with canola oil, only palm oil was able to maintain β′ stability.