Studies of the Formation and Stability of Urea Inclusion Compounds

Abstract

A study was undertaken to determine the relative ease of formation and stability of straight-chain primary and secondary alkanols capable of forming urea inclusion compounds. The compounds studied were 1-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 1-octanol, 3-octanol, 4-octanol, 1-nonanol, 4-nonanol, 5-nonanol, 1-decanol, 1-undecanol, and 1-dodecanol. 1-Heptanol was the shortest alcohol that formed an inclusion compound by the procedure employed. The ease of formation of a straight-chain alcohol was proportional to the number of uninterrupted methylene groups (—CH₂—) present. The ease of urea inclusion compound formation generally decreases as the functional group approaches the center of the chain. These conclusions were based on X-ray powder diffraction measurements and the weight of recovered products under equilibrium conditions.     

The coalescence of n-hexane droplets in aqueous solutions of n-alcohols

Coalescence times, measured by high speed cinematography, are reported for n-hexane droplets formed and grown on adjacent nozzles in equilibrated aqueous solutions of ethanol, n-butanol, n-hexanol, n-octanol, n-decanol and n-dodecanol. The drops remained attached to the nozzles throughout the coalescence process. Coalescence times increased when alcohols were added to the system. Very similar results were obtained for the alcohols n-hexanol to n-dodecanol. When these alcohols, which are much more soluble in n-hexane than in water, were present, the observed coalescence times could be accounted for best by considering diffusion processes occurring in the n-hexane. For ethanol and n-butanol, which are more soluble in water, diffusion processes occurring in the water had to be considered as well.     

改进的氢溴酸-浓硫酸法合成1-溴辛烷

以工业废氢溴酸(48%)为原料,在浓硫酸存在下,与正辛醇进行反应合成1-溴辛烷。考察了反应条件对产率的影响,结果表明,比较合适的反应条件为:正丁醇∶氢溴酸∶浓硫酸(摩尔比)=1∶1.15∶1.38,反应时间3 h,反应温度110~115℃,产率达到99.0%。粗产品经气相色谱分析证明几乎无副产物,产品经IR和折光率进行表征。     

Extraction of Nitric Acid into Alcohol: Kerosene Mixtures

Abstract

Nitric acid extraction from 0.1 mol/L – 5 mol/L nitric acid into varied volume fractions (5%–100%) of long-chain aliphatic alcohols (1-hexanol, 1-octanol, 2-ethylhexanol, 1-decanol) in alkanes (different kerosenes, n-dodecane, isooctane) was measured. At equal molar alcohol concentration, 1-hexanol, 1-octanol, and 1-decanol extract equal amounts of nitric acid. The amount of nitric acid extracted into 2-ethylhexanol is approxmately half compared to 1-octanol. The alkane does not influence nitric acid extraction. Extraction can accurately be calculated taking into account the formation of a species (HNO₃)(ROH)₂. Due to the change in diluent properties with alcohol volume fraction, conditional equilibrium constants must be used.     

The preparation of alkyl esters from highly unsaturated triglycerides

The alcoholysis reaction has been applied to the preparation of highly unsaturated alkyl esters from menhaden oil. This reaction proceeded very rapidly, and nearly quantitative yields were obtained with virtually, no loss in double-bond structure. The formation of esters was studied, using straight- and branched-chain alcohols having 1–6 carbon atoms. The reactions were monitored by the technique of thin-layer chromatography (TLC). Maximum conversion of straight-chain esters was found to be a linear function with respect to the number of carbon atoms in the alcohol. Reaction time varied from 2 min for methanol to 60 min for n-hexanol. Branched-chain alcohols reacted more slowly than did the corresponding straight-chain compounds. This reaction was found to be applicable to laboratory and large scale preparations of highly unsaturated alkyl esters. Presented at the AOCS meeting, St. Louis, Mo., 1961.     

Improvement in the gas chromatographic resolution of petroselinate from oleate

In the extraction of oils from seeds of the genus Coriandrum, GC separations of petroselinate from oleate often gave poor resolution of these two isomers. Oleic and petroselinic acids were esterified with a series of alcohols (methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 3-methyl-1-butanol, and 2-ethyl-1-hexanol). GC resolution of the Δ6 from the Δ9 and Δ11 octadecenoates was examined for all ester derivatives on a polar phase column. The Δ6 and Δ9 isomers were unresolved as methyl esters; however, the 2-ethyl-1-hexyl esters gave baseline separation of all three isomers under temperature programming conditions. When isothermal conditions were optimized for each ester, separation of these isomers was possible with good resolution values (>89%) for all the alcohols except methanol, which had a partial resolution of 51%. The rates of esterification of all the alcohols were determined for reactions with both oleic acid and triolein using potassium hydroxide as the esterification catalyst. Methanol gave the largest rate constant in both acid and oil esterification reactions with a rate constant 10-fold better than all of the other alcohols. Based on rates of reaction, resolution of petroselinate from oleate, and removal of residual alcohol, the ethyl ester derivative appears to be the best choice for seed oils containing petroselinic acid.     

Kinetics of the formation of symmetrical wax esters from the corresponding alcohols with the use of hydrobromic acid and hydrogen peroxide

The primary aliphatic alcohols n-octanol, n-decanol, and n-dodecanol have been converted to their corresponding symmetrical esters by using HBr and H₂O₂ in the absence of a solvent. The reaction was carried out at 30, 40, and 50°C and at mole ratios of alcohol to HBr of 1∶0.1, 1∶0.2, 1∶0.3, and 1∶0.5. The rate of the reaction was found to increase with increase in the reaction temperature and concentration of HBr. The maximal conversion of n-octanol was 72% at 40°C and a mole ratio of n-octanol to HBr of 1∶0.5. The kinetics of the reaction have been established, and the reaction was found to be first-order with respect to alcohol and bromine concentration in the organic phase, and second-order with respect to both. The second-order rate constants for n-octanol, n-decanol, and n-dodecanol are 27.08, 32.58, and 37.42 mL mol⁻¹ min⁻¹, respectively, at 40°C. The activation energy for the esterification reaction of n-octanol was found to be 16.32 kcal mol⁻¹.     

酸化膨润土催化酯化合成癸二酸二正己酯

以酸化膨润3a（SO4^2-／Bentonite）固体酸为催化剂、癸二酸和正己醇为原料合成了癸二酸二正己酯。考察了反应温度、原料配比、催化剂用量和反应时间等因素对酯化反应的影响,得到了较佳酯化反应工艺条件：正己醇与癸二酸的物质的量比为4．0：1,SO4^2-／Bentonite用量为醇酸总质量的4．17％、反应温度不高于160℃、反应时间为3h,此条件下癸二酸的转化率达到99．05％。催化剂重复使用3次,癸二酸的转化率仍可达93％以上。     

Synthesis of secondary ethers derived from meadowfoam oil

Secondary ethers can be obtained from meadow-foam-derived delta lactones or 5-hydroxy fatty acids by using Lewis or Brønsted acid catalysts in good yield (70–90%). The conversion of δ-lactone or 5-hydroxy fatty acid to 5-ethers is performed under atmospheric pressure between 67 and 125°C with 0.5–6.4 mole equivalents of acid catalyst in the presence of 2–40 equivalents of alcohol and a reaction time of 1–140 h. Acid catalysts include mineral acids, such as perchloric and sulfuric; Lewis acids, such as boron trifluoride; and heterogeneous catalysts, such as clays and ion-exchange resins. Primary alcohols, such as methanol, butanol, decanol, and oleyl alcohol, or branched-chain alcohols, such as 2-ethylhexanol, can be used to make secondary ether fatty esters. The 5-ether fatty esters and the process for their formation have not been previously known and appear to be limited to structures where stabilized cations can be formed. The novel ethers were fully characterized by nuclear magnetic resonance and gas chromatography-mass spectrometry.     

纳米Y_2O_3催化合成无毒增塑剂柠檬酸三丁酯

用柠檬酸和正丁醇为原料,以纳米Y2O3催化合成无毒增塑剂柠檬酸三丁酯,探讨了催化剂用量、酸醇物质的量比、反应时间、反应温度对酯化率的影响,对合成的产品进行红外光谱分析。实验结果表明,纳米Y2O3催化合成柠檬酸三丁酯的最佳条件为:n(柠檬酸)∶n(正丁醇)=1∶4.5,催化剂用量为柠檬酸质量的3.5%,反应温度114~153℃,反应时间2.5 h,酯化率可达90.06%,产品纯度>98.88%。     

固体超强酸S2O2-8/TiO2催化合成癸二酸二正己酯

以癸二酸和正己醇为原料,固体超强酸S²O^2-₈/TiO₂ 为催化剂合成了低温增塑剂癸二酸二正己酯。考察影响反应的各种因素,最佳反应条件为：癸二酸用量0.05 mol,醇酸物质的量比为2.4,催化剂用量0.5 g,带水剂环己烷5 mL,反应时间2.0 h,酯化率达89.7%,表明固体超强酸S²O^2-₈/TiO₂ 是合成癸二酸二正己酯的优良催化剂。     

The addition of alkoxy side-chains to biodiesel and the impact on flow properties

Butyl biodiesel was synthesised from canola oil and subsequently epoxidised via the in situ peroxyacetic acid method converting 45% of the unsaturated portion. Alkoxy butyl biodiesel was synthesised under acid conditions with a range of both straight-chain and branched alcohols. Alkoxylation of butyl biodiesel with methanol, ethanol and n-propanol did not improve the cloud or pour point over that for conventional methyl biodiesel. Alkoxylation with alcohols larger than butanol including n-pentanol, n-hexanol and n-octanol produced cloud points that were 5 °C lower than that for methyl biodiesel. The lowest cloud point achieved was for 2-ethylhexoxy butyl biodiesel at −6 °C, representing a 6 °C reduction in cloud point over methyl biodiesel. Alkoxylation did not have a significant effect on the pour point of biodiesel. Alkoxylation of butyl biodiesel resulted in significant increases in viscosity. The kinematic viscosity generally increased with increasing alkoxy chain length and ranged from 6.67 mm² s⁻¹ for methoxy butyl biodiesel to 9.76 mm² s⁻¹ for ethylhexoxy butyl biodiesel, more than double the value for methyl biodiesel. The improved low-temperature properties of the longer-chain alkoxy biodiesel were most likely due to the protruding alkoxy chain, which also resulted in an increase in viscosity. The use of alcohols larger than pentanol does not provide significant benefit in terms of low-temperature properties, and results in an undesirable increase in viscosity.     

对甲苯磺酸铜催化合成乙酸辛酯

以对甲苯磺酸铜为催化剂,不用溶剂,对乙酸与正辛醇之间的酯化反应进行了研究,考察了醇酸物质的量比、催化剂用量、反应时间对乙酸辛酯收率的影响。结果表明,对甲苯磺酸铜有着良好的催化活性,在正辛醇用量0.1 mol,n(正辛醇)∶n(乙酸)=1∶2.5,催化剂用量为反应物总质量的0.75%,回流反应50 min条件下,乙酸辛酯收率可达88.5%,催化剂重复使用5次仍保持较高活性。     

浆态鼓泡床反应器合成乙酸正丁酯工艺的研究

采用浆态鼓泡床反应器,改性阳离子交换树脂作催化剂,正丁醇和冰乙酸为原料,对乙酸正丁酯的合成工艺进行了研究,确定了最佳工艺条件:反应温度为110℃,反应时间75min,原料摩尔比n(正丁醇)∶n(乙酸)=1.2∶1,催化剂用量占乙酸用量的40%,乙酸正丁酯的产率可达到98%以上。     

树脂催化合成无毒增塑剂柠檬酸三辛酯

以树脂作催化剂,合成柠檬酸三辛酯。探讨了催化剂用量、反应温度、酸醇摩尔比和反应时间等因素对酯化反应的影响。结果表明:在150℃,酸醇摩尔比为1∶4.5,催化剂用量为柠檬酸质量的10%,反应1.5 h后,酯化率达到97%以上。催化剂的性能较好,便于与产物分离,可以回收使用。     

Kinetics of the reaction between urea and formaldehyde in the presence of sulfuric acid

The kinetics of the reaction between urea and formaldehyde were studied in the presence of various amounts of sulfuric acid (5–45% by weight) at different temperatures (5°, 15°, and 25°C). The reaction was shown to follow first-order kinetics. The activation energy for the reaction varies from 12.51 kcal/mole to 14.59 kcal/mole in the range of sulfuric acid concentration studied.     

HBSS型琥珀酸(混合)双酯磺酸钠盐加脂剂的合成

以十六醇、正丁醇、马来酸酐为主要原料,合成了十六烷基正丁基琥珀酸(混合)双酯磺酸钠盐皮革加脂剂,对合成反应条件进行了优化。优化的十六醇与马来酸酐的单酯化反应条件为:n(十六醇):n(马来酸酐)=1:1.05,反应温度90℃,反应时间2.5h;十六烷基马来酸单酯与正丁醇双酯化反应条件为:n(十六烷基马来酸单酯):n(正丁醇)=1:1.5,反应温度130℃,反应时间90min,w(对甲苯磺酸)=0.5(基于总反应物的质量);十六烷基正丁基马来酸(混合)双酯与亚硫酸氢钠的磺化反应条件为:n〔十六烷基正丁基马来酸(混合)双酯〕:n(NaHSO3)=1:1.1,反应温度100℃,反应时间4h。该加脂剂具有较好的乳化能力,可以乳化自身质量33的鱼油。用IR表征了目标产物结构。     

粗苯甲酸甲酯醇解合成苯甲酸丁酯的工艺研究

研究开发了由对苯二甲酸二甲酯生产过程中副产物粗苯甲酸甲酯合成苯甲酸丁酯的工艺过程。分酯过量与醇过量两种情况分别考察了反应配料比、催化剂用量、反应温度和回流比对转化率的影响 ,确定了最佳工艺条件。实验表明 ,在钛酸酯存在下 ,当醇酯摩尔比为 1.5∶1、催化剂用量为 1%、回流比为 2∶2时 ,反应转化率达 82 .79%。     

甲苯-4-磺酸催化高效合成尼泊金正丁酯防腐剂

以对羟基苯甲酸和正丁醇为主要原料,甲苯-4-磺酸为催化剂,正丁醇为带水剂,催化合成尼泊金正丁酯。考察了原料对羟基苯甲酸和正丁醇的摩尔比、催化剂用量、反应温度和反应时间等对反应的影响。结果表明,适宜的反应条件:以0.02 mol对羟基苯甲酸计,n(正丁醇)∶n(对羟基苯甲酸)=4∶1,m(甲苯-4-磺酸)∶m(对羟基苯甲酸)=0.12∶1,反应温度140℃,反应时间3 h。该条件下,重复实验3次,尼泊金正丁酯收率均达99%以上。     

杂多酸催化合成丁二酸二丁酯研究

采用均匀设计，以Keggin型磷钨酸为催化剂，甲苯为带水剂，得到了合成丁二酸二丁酯的最佳工艺条件为：醇酸物质的量比3．0：1，催化剂量为酸质量的1．1％，带水剂量为反应体系总质量的22％，反应时间2h，最高酯化率99．47％。