共查询到20条相似文献,搜索用时 15 毫秒
1.
A. M. Motawie E. A. Hassan A. A. Manieh M. E. Aboul-Fetouh A. Fakhr El-Din 《应用聚合物科学杂志》1995,55(13):1725-1732
Linseed oil was epoxidized in situ with perbenzoic or peracetic acid to produce epoxidized linseed oil (I). Effect of type and concentration of the peracid and the reaction time on the characteristics of the produced epoxidized oil were studied. Various epoxidized polyurethanes (II) with different NCO/OH ratios as well as epoxidized polyesters (III) were prepared from (I). The results obtained for the evaluation of resins (II) and (III) show promising applicability as petroleum pipeline coatings. © 1995 John Wiley & Sons, Inc. 相似文献
2.
The following furanoid fatty acids were detected in soya-bean oil (SBO), wheat germ oil, rapeseed oil and corn oil: 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid(I),10,13-epoxy-11,12-dimethyloctadeca-10,12-dienoid acid (II), 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid (III). A model experiment indicated that II and III were quickly photooxidized with formation of the intense flavour compound 3-methyl-2-4-nonanedione (MND) as secondary product. MND causes the light-induced off-flavour of SBO. A method for the quantification of the three furanoid fatty acids in vegetable oils was developed. The amounts of II and III were relatively high (0.02-0.04%) in unprocessed and refined SBO and in one sample of wheat germ oil and quite low (0.0015–0.0035%) in corn oil and rapeseed oil. The furanoid fatty acids I, II and III were absent on olive and sunflower oils. 相似文献
3.
The effect of fatty acid composition on the acrylation kinetics of epoxidized triacylglycerols 总被引:1,自引:0,他引:1
Epoxidized oils, epoxidized triacylglycerols, and epoxidized fatty acid methyl esters were made by reaction with performic
acid formed in situ. The extent of epoxidation was ca. 95% for all of the epoxidized samples, as determined by 1H nuclear magnetic resonance. The epoxidized samples were reacted with an excess of acrylic acid for different reaction times.
The acrylation reaction was found to have a first-order dependence on the epoxide concentration for all oils, pure triacylglycerols,
and fatty acid methyl esters. However, the rate constant of acrylation was found to depend on the composition of the epoxidized
material. The acrylation rate constant for 9,10-epoxystearic acid was 96 L2/(mol2·min). The rate constant of acrylation for the epoxides on 9,10,12,13-diepoxystearic acid was 60 L2/(mol2·min). The acrylation rate constant for the epoxides on 9,10,12,13,15,16-triepoxystearic acid was 50 L2/(mol2·min). Thus, the rate constant of acrylation increased as the number of epoxides per fotty acid decreased. Multiple epoxides
per fatty acid decrease the reactivity of the epoxides because of steric hindrance effects, and the oxonium ion, formed as
an intermediate during the epoxyacrylic acid reaction, is stabilized by local epoxide groups. These results were used to derive
an acrylation kinetic model that predicts rate constants from fatty acid distributions in the oil. The predictions of the
model closely match the experimentally determined rate constants. 相似文献
4.
Summary Linseed oil was epoxidised by 60% per acetic acid to produce epoxidised linseed oil. By this process, two new groups entered
the molecule (epoxy group and hydroxyl group). These groups were detected by using infrared (IR) analysis.
Product (I) reacted with phenol in different ratios by weight percent to produce Phenolic epoxidised resin (II). Product (II)
reacted with toluene diisocyanate to produce product (III), Phenolic epoxidised polyurethane, which had an excellent adhesion
character. Product (III) was examined chemically and physically according to ASTM-API standard methods.
The results provide encouragement for their use as a petroleum tank coating material. They can be used as a one-layer coating
which combines the properties of more than coating of two layers because it combines more than one function group. 相似文献
5.
Influence of n-3 Fatty Acids on Mitochondrial Function and Stability of Erythrocyte Membrane of Rats in Long Term Experiments with Cod Liver Oil The influence of different amounts of polyunsaturated fatty acids (PUFA) (1.3, 2.6 and 6.3% of total energy intake) on mitochondrial respiration and the stability of erythrocyte membrane was tested in experiments with rats lasting 12 and 32 weeks. The fat component of the semisynthetic diets (6g/100 g diet) was made up of coconut fat and cod liver oil (Gr. I, II, III) and cod liver oil and linoleic methylester (G1. IV). The n-3 fatty acids amounted to 1.18 cal% (I), 2.35 cal% (II,III) and 2.1cal% (IV). The diets of the groups I, III and IV wre supplemented with 6 mg D-α-tocopherylequivalents per 100g; the tocopherol/PUFA-ratios (mg/g) in the diets I, II, III, IV were 10.7, 0.1, 5.4 and 2.3 respectively. After 12 weeks cod liver oil had no significant influence on total lipids of the liver, hemolysis rate of red blood cells as well as the respiration of liver mitochondria. Highest weight gained was reported for the animals of group I receiving 1.3 cal% of PUFA derived from cod liver oil. All groups had similar relative liver weights. After 32 weeks the consequences of the insufficient supply tocopherol in group II were a significantly increased hemolysis rate of the erythrocytes and a decreased respiratory control index as well as the ADP/O-ratios of liver mitochondria using succinate and malate/glutamate as substrates. The highest PUFA amount fed (6.3 cal%; derived from cod liver oil and linoleic methylester) with the adequate vit. E supplementation did not cause any major alterations. The results show that fatty acids of the α-linolenic acid group can replace in part the n-6 fatty acid in their essential role for integrity of the membranes of mitochondria and erythrocytes. This is possible only if the increased antioxidant requirement of the body caused by ingestion of fish oil PUFA's is adequately compensated through additional supplements with antioxidants like α-tocopherol. 相似文献
6.
Epoxidized polyurethane was synthesized from the reaction of the prepared epoxidized linseed oil with toluene diisocyanate (TDI) at a NCO-to-OH ratio equal to 5. The prepared epoxidized linseed oil was also reacted with phthalic anhydride at a molar ratio of 1 : 4 to give epoxidized polyester. Epoxidized polyurethane and epoxidized polyester were mixed in different weight ratio percentages to give three types of epoxidized (polyurethane-polyester) resin systems. These resin systems were tested physically and chemically and evaluated as coatings for both metal and glass panels. The data obtained indicate an exceptional combination of properties, such as adhesion, bending, and chemical resistance of the epoxidized (polyurethane-polyester) resin system of the weight ratio percentage of 15 : 85. Thus, these materials can be recommended to be used as coating materials. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 577–581, 1998 相似文献
7.
Ramesh Kumar Selvaraj Gita Cherian 《European Journal of Lipid Science and Technology》2004,106(1):3-10
The splenocyte fatty acid profile and immune response of broiler chickens were investigated. One hundred and twenty day‐old broiler chicks were fed diets containing conjugated linoleic acid (CLA) (Diet I), sunflower oil (Diet II), flaxseed oil (Diet III) or fish oil (Diet IV). The total lipid content of the diets was 3.5%. Body weight and feed intake was higher (P <0.05) in Diet IV compared to Diets I, II and III. Birds fed Diet III and IV had a higher content of n‐3 fatty acids in splenocytes than those fed Diets I and II. Serum anti‐BSA immunoglobulin content was higher (P <0.05) in birds fed Diets III and IV, compared to those fed Diets I and II. Delayed type hypersensitivity response, measured as the wing web skin swelling reaction (thickness) to Mycobacterium butyricum injection (s.c.), increased (P <0.05) from 0.71 and 0.98 mm in Diets IV and III, respectively, to 1.19 and 1.41 mm in Diets I and II, respectively. The number of CD4+ and CD8+ blood lymphocytes and CD4+, CD8+ and IgM+ splenocytes did not differ (P >0.05) between treatment groups. N‐3 fatty acids increased production performances and antibody mediated responses, while n‐6 fatty acids and conjugated linoleic acid increased cell mediated responses in broiler birds. 相似文献
8.
Ferial M. Atta 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,61(3):225-229
3-(2′-Chloroethyl)-2-methyl-3,4-dihydroquinazolin-4-one ( I ) was reacted with sodio (sodium thioglycolate) in dry dioxane and yielded compound II . By using thionyl chloride, this compound was converted to the corresponding acid chloride ( III ). The prepared acyl chloride ( III ) was allowed to interact with different α-amino acids such as Gly, L -Ala, L -B-Phe, DL -Asp, L -Glu, L -Thr and L -Val to give new amino acid derivatives ( IVa – g ). A selected C-terminal derivative of glycine ( IVa ) was converted into acid chloride ( V ). The acid chloride formed was reacted with L -Ala, L -B-Phe, DL -Asp, L -Glu, L -Thr and L -Val and yielded the new dipeptides VIa – f . The structures of the synthesized compounds were elucidated by elemental analysis and IR spectra. The prepared peptides were tested for their antimicrobial activities by comparison with tetra-cycline as a reference compound. 相似文献
9.
Jonathan A. Zerkowski Michael J. Haas 《Journal of the American Oil Chemists' Society》2011,88(8):1229-1237
This paper reports the synthesis of a series of novel compounds where carboxylic acids have been linked to a phenol through
amidomethyl units. For instance, one, two, or three fatty acids have been selectively appended to the phenol in yields above
75%. The fatty acid used was oleic acid, which was subsequently epoxidized. Other functional groups, such as amino acids,
can be incorporated in these compounds. Examples of monomers that are suitable for polymerization were also prepared: one
acrylamide, one styrene derivative, and two types of AB2 diamino acids, all of which contain oleic units that are sites for epoxidation and crosslinking. Fatty acid aryl ethers were
prepared using hydroxy fatty acids. These molecules are intended to serve as augmented analogues of epoxidized vegetable oil.
Their amide groups should lead to intermolecular aggregation through hydrogen bonding, and the option to covalently include
other functional groups may permit tuning of the macroscopic materials properties of films, coatings, or solids constructed
from them. 相似文献
10.
Lucas J. Stolp Eugene Joseph Dharma R. Kodali 《Journal of the American Oil Chemists' Society》2019,96(11):1291-1302
Plasticizers are nonvolatile organic liquids that impart flexibility to polymers. Due to environmental, health, and safety reasons, the industry is looking for bioplasticizers to replace petroleum-derived phthalates. To fulfill this need, soy fatty acid ester estolides were synthesized, characterized, and evaluated as phthalate replacements. Soybean oil was transesterified with methanol or glycerol to form lower molecular weight fatty acid esters that were epoxidized and ring opened with acetic acid and acetylated to give the final products. Ring opening and acetylation of the epoxidized oleic acid esters gave acyclic acetate fatty acid ester estolides, whereas the polyunsaturated fatty acid esters, linoleate, and linolenate gave cyclic tetrahydrofuran derivatives and cross-linked higher molecular weight materials. The cyclization mechanism to form the tetrahydrofuran derivatives was postulated. Soy fatty acid ester estolides were compounded with formulated poly(vinyl chloride), (PVC) and tested for their functional properties. The physical and functional properties of the new bioplasticizers were compared with commercial plasticizers. The elasticity of PVC compounded with experimental plasticizers and commercial phthalates was comparable. PVC compounded with fatty acid methyl ester estolide showed lower glass transition temperature and similar tensile properties compared to PVC compounded with the commercial phthalate. PVC compounded with the glyceryl fatty acid ester estolide showed a higher glass transition temperature, higher tensile properties compared to PVC compounded with the commercial phthalate. 相似文献
11.
Revisiting the Enzymatic Epoxidation of Vegetable Oils by Perfatty Acid: Perbutyric Acid Effect on the Oil with Low Acid Value
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Wei Liu Jingnan Chen Ruili Liu Yanlan Bi 《Journal of the American Oil Chemists' Society》2016,93(11):1479-1486
Enzymatic epoxidation of vegetable oils in the presence of free fatty acids has been well studied in recent years, by mainly using long chain fatty acids (e.g., stearic acid) as the active oxygen carrier. However, for the previous enzymatic processes, the acid value (AV) of final epoxidized oils using long chain fatty acids is high, and the free fatty acid is not easily removed in the post treatment with water. Aiming at developing a more sustainable process, enzymatic epoxidation of sunflower oil was revisited using different free fatty acids catalyzed by Novozym 435 (lipase B from Candida antarctica, provided by Novozymes, Bagsvaerd, Denmark). When long chain stearic acid was introduced into the epoxidation in toluene solvent, the epoxy oxygen group content (EOC) of 6.41 ± 0.19 % was obtained. Due to the poor water solubility of stearic acid, the AV of the final epoxidized oil product was very high (53.40 ± 1.34) after it was washed with water. Alternatively, current study shows that the epoxidation process using short chain butyric acid produced the final epoxidized oil with lower AV of 2.57 ± 0.11. When the enzymatic epoxidation of sunflower oil was optimized in the presence of butyric acid and Novozym 435, EOC of 6.84 ± 0.21 % was obtained, reaching an oxriane conversion of 96.4 ± 3.0 %. Therefore, introducing short chain butyric acid as an active oxygen carrier will provide an alternative to the present enzymatic epoxidation process and produce the desired epoxidized oil products with much lower AV only after simple water‐treatments, which will make the enzymatic epoxidation more attractive. 相似文献
12.
A fast and cost-effective procedure to quantitate epoxidized soybean oil by means of an external standard method is reported.
This procedure is applicable to commercial epoxidized oils, polymer additive packages and polymers—polyvinyl chloride (PVC)—containing
epoxidized oils. The epoxidized soybean oil is converted into fatty acid methyl esters with tetramethylammonium hydroxide,
and analyzed by capillary gas chromatography with flame-ionization detection. In PVC samples, the epoxidized soybean oil was
extracted with toluene and followed by derivatization prior to analysis. The methyl esters of monoepoxyoctadecanoic, diepoxyoctadecanoic
and triepoxyoctadecanoic acid were separated with a short capillary column. 相似文献
13.
通过薄层色谱、气相色谱、色质联用等技术,首次得到了油脂环氧化反应期间的脂肪酸环氧化反应规律:开始反应阶段,高含量不饱和脂肪酸反应速率高于低含量不饱和脂肪酸;环氧化反应期间,多不饱和脂肪酸首先生成单环氧酸,之后再逐渐生成二环氧酸,最后生成三环氧酸;富含亚麻酸的油脂环氧化反应时有更易于开环反应的趋向,其次是富含亚油酸的油脂,再次是富含油酸的油脂.实验结果表明,不同环氧油原料在进行环氧化反应时需要控制不同的反应条件,以避免开环副产物量的增加,从而制备得优质环氧油产品. 相似文献
14.
Mengguo Yan Elizabeth M. Frank Eric W. Cochran 《Journal of the American Oil Chemists' Society》2018,95(2):209-216
In this article, we investigate the role of triacylglycerol composition on the properties of epoxidized vegetable oils and the kinetics of the epoxidation process under conditions comparable to commercial epoxidation. Commodity soybean oil (24% oleic acid, 50% linoleic acid, and 7% linolenic acid), high‐oleic soybean oil (75% oleic acid, 8% linoleic acid, and 2.5% linolenic acid), and linseed oil (11% oleic acid, 15% linoleic acid, and 64% linolenic acid) were each epoxidized to various extents. Epoxidation rate, viscosity, differential calorimetry, and X‐ray diffraction data are presented for these oils and interpreted in the context of their fatty acid profile (mostly oleic, linoleic, or linolenic). While fully epoxidized soybean oil is widely commercially available and used in an increasing array of industrial applications, information relating to partially epoxidized oils and epoxidized oils of other cultivars is less well known. 相似文献
15.
Yonghui Li Cong Li Xiuzhi Susan Sun 《Journal of the American Oil Chemists' Society》2019,96(9):1035-1045
Plant oil triacylglycerols are attractive renewable resources for biobased epoxy resins. We investigated the curing kinetics of three model epoxidized fatty acid methyl esters and representative epoxidized triacylglycerols with varied epoxide functionalities and distributions in the presence of a latent cationic initiator. Isothermal differential scanning calorimetry (DSC) was used to analyze the curing kinetics of the epoxy systems, and kinetic parameters (i.e., rate constants, reaction orders) were determined. Both epoxidized fatty esters and triacylglycerols followed the autocatalytic curing mechanism, and the DSC data were analyzed according to the Kamal autocatalytic model. Epoxidized methyl linoleate (EMLO) had the highest maximum curing rate, followed by epoxidized methyl linolenate (EMLON), and epoxidized methyl oleate (EMO) had the lowest maximum curing rate. We conclude that EMLO with two epoxide groups has the highest reactivity in this curing system, while the EMO with one epoxide group has the lowest reactivity. For epoxidized triacylglycerols, epoxidized camelina oil had the highest curing reactivity at higher temperatures, followed by epoxidized linseed oil and soybean oil. 相似文献
16.
17.
Jiaojiao Fang Ting Zheng Zhenyu Wu Lihang Wu Qinglong Xie Fan Xia Meizhen Lu Yong Nie Jianbing Ji 《Journal of the American Oil Chemists' Society》2019,96(8):955-965
Epoxidized oils are eco-friendly plasticizers, which are industrially produced through the epoxidation reaction in a formic acid-hydrogen peroxide autocatalyzed system. The fundamental knowledge to describe the phase equilibrium of systems after epoxidation reaction is lacking, which is crucial for the design of the purification facilities. This work reported experimental data for the liquid–liquid equilibrium of three systems, i.e., epoxidized fatty acid methyl esters + formic acid + water, epoxidized fatty acid 2-ethylhexyl esters + formic acid + water, and epoxidized soybean oil + formic acid + water, in the temperature range (303.15–348.15) K under atmospheric pressure. The results indicated that the liquid–liquid equilibrium constant of formic acid in the systems followed the order of epoxidized fatty acid 2-ethylhexyl esters > epoxidized fatty acid methyl esters > epoxidized soybean oil. Moreover, the obtained experimental data were correlated using nonrandom two liquid (NRTL) and universal quasi chemical (UNIQUAC) models. The maximum root mean square deviation (RMSD) values as low as 0.0052 and 0.0263 were estimated using the NRTL and UNIQUAC model, respectively. The NRTL model is more suitable than the UNIQUAC model to describe the liquid–liquid equilibrium behavior of these ternary systems. 相似文献
18.
Novel two pack polyurethane wood finished coatings are prepared from renewable sources, such as vegetable oil based fatty acid and dimer fatty acid. In actual experimental part oleic acid was reacted with diethanolamine to obtain amide which was on condensation polymerization with dimer fatty acid converted into the polyesteramide polyol. These are all being used to prepare polyurethanes. The functional and structural elucidation of dimer fatty acid based polyesteramide and diethanolamide were carried out by end group analysis, spectral studies such as FTIR and 1H NMR. Average molar masses of the polyesteramide were estimated by gel permeation chromatography (GPC). The polyesteramide was used in the preparation of wood finished polyurethane coatings by reacting it with aromatic diisocyanates. Thermogravimetric analysis (TGA) was used to study the thermal behavior of coatings. Physico-chemical and coating properties of the coatings were investigated by using standard methods. The results indicated that the bio-based wood finished PU coatings provided good mechanical, weather resistance as well possessed adequate coating properties for wood surface protections. 相似文献
19.
This work deals with the synthesis and characterization of a novel polyesteramide (PEA) hot melt adhesive (HMA) using dimer acid, ethylenediamine, and modified jatropha seed oil. Jatropha seed oil was initially reacted with diethanolamine to prepare N,N-bis(2-hydroxyethyl) jatropha oil fatty amide (HEJA), having hydroxyl end groups. HEJA was reacted with dimer acid as a partial replacement of ethylenediamine. Ethylenediamine was replaced up to 30% by HEJA, on molar basis. Prepared PEA HMAs were characterized for mechanical, thermal, rheological, and adhesion properties. Increased replacement of ethylenediamine by HEJA led to decreased tensile strength, melting temperature, enthalpy of melting, crystallization temperature, enthalpy of crystallization, glass transition temperature, lap shear strength, T-peel strength, and viscosity. This was due to the reduction in hydrogen bond formation capacity, and thus the intermolecular forces of attraction of the ester and secondary amide linkages as compared to primary amide linkages, and the increased distance between ester linkages as compared to the primary amide linkages, was caused due to the bulky nature of HEJA. However, HMAs prepared using HEJA will have better low temperature flexibility due to low Tg; and better adhesion process due to the lower viscosity and melting temperature. 相似文献
20.
Mahua (Madhuca indica) is a widely grown tree in tropical regions of India. The estimated annual production of it is higher as compared to karanja oil and neem oil. In the present work mahua oil was reacted with diethanol amine resulting in the formation of mahua oil fatty amide (MFA) which was further reacted with bisphenol-A forming mahua polyetheramide resin (MPEA). The structures of the synthesized intermediate and polyetheramide resin were confirmed by spectroscopic methods and estimated physico-chemical properties like acid value, iodine value, saponification value, hydroxyl and acid value. The prepared MPEA resin was converted to polyurethane coatings by reacting with methylene diphenyl diisocyanate (MDI) and toluene diisocyanate (TDI) with 1.1:1 NCO/OH ratio. Thermal stability and coating properties of polyurethane coatings on steel panels and particle board panels were investigated. The coating performance of the resin was tested by measurement of gloss, mar resistance, flexibility, scratch, pencil hardness, adhesion and chemical resistance using standard methods. The results presented better physico-mechanical as well as corrosion resistance performance of the polyurethane coating obtained from mahua oil based polyetheramide resin. 相似文献