Fatty acid-based alkyd resins prepared with different amounts of glycerol and pentaerythritol were characterized. Sacha inchi oil and linseed oil (comparative purposes) were used as fatty acids’ sources. FT-IR and 1H NMR spectroscopy were done for alkyd structural verification. Alkyd resins were evaluated through physico-chemical (colour, density, viscosity) and thermal characterization. Film coating performance (drying, hardness, chemical resistance) was also studied. The oxidative crosslinking time tendency was corroborated by the quartz crystal microbalance (QCM) technique. Alkyd resins obtained with fatty acids from sacha inchi and linseed oils had similar properties. Results indicated that lighter resins can be obtained from sacha inchi oil, whereas pentaerythritol increases viscosity and thermal stability, and retards drying time of fatty-acid based alkyd resins. 相似文献
The main triacylglycerol (TAG) composition of different plant oils (almond, avocado, corn germ, grape seed, linseed, mustard seed, olive, peanut, pumpkin seed, sesame seed, soybean, sunflower, walnut and wheat germ) were analyzed using two different mass spectrometric techniques: HPLC/APCI-MS (high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry) and MALDI-TOFMS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry).Linear discriminant analysis (LDA) as a multivariate mathematical statistical method was successfully used to distinguish different plant oils based on their relative TAG composition. With LDA analysis of either APCI-MS or MALDI-MS data, the classification among the almond, avocado, grape seed, linseed, mustard seed, olive, sesame seed and soybean oil samples was 100% correct. In both cases only 6 different oil samples from a total of 73 were not classified correctly. 相似文献
Sunflower, soybean, and linseed oils are renewable resources that can be readily epoxidized. Epoxidation of these oils has the potential for use as an environmentally friendly, reactive material in pigmented formulation, designed for use as functional coatings. This study concern the synthesis of phthalimide modified epoxy compounds through reacting N‐(2‐hydroxyethyl) phthalimide (HEP) with epoxidized sunflower, soybean and linseed oils. The resulting compounds possessed both oxirane ring and phthalimide group. Incorporation of phthalimide group into epoxy resins provided cyclic imide structure and high cross‐linking density to the stoved resins, to achieve good mechanical characteristics and high chemical resistance to these resins. The films of phthalimide sunflower, soybean and linseed‐based epoxy resins were found to be similar with respect to resistance to water, alkali, acids, and solvents as well as gloss%, adhesion, impact, hardness, bending, and flexibility. 相似文献
Because of its complex nature, the analysis of deodorizer distillate is a challenging problem. Deodorizer distillate obtained from the deodorization process of vegetable oils consists of many components including free fatty acids, tocopherols, sterols, squalene and neutral oil. A gas chromatographic method for the analysis of deodorizer distillate without saponification of the sample is described. After a concise sample preparation including derivatization and silylation, distillate samples were injected on column at 60 degrees C followed by a gradual increase of the oven temperature towards 340 degrees C. The temperature profile of the oven was optimized in order to obtain a baseline separation of the different distillate components including free fatty acids, tocopherols, sterols, squalene and neutral oil. Good recoveries for delta-tocopherol, alpha-tocopherol, stigmasterol and cholesteryl palmitate of 97, 94.4, 95.6 and 92%, respectively were obtained. Repeatability of the described gas chromatographic method was evaluated by analyzing five replicates of a soybean distillate. Tocopherols and sterols had low relative standard deviations ranging between 1.67 and 2.25%. Squalene, mono- and diacylglycerides had higher relative standard deviations ranging between 3.33 and 4.12%. Several industrial deodorizer distillates obtained from chemical and physical refining of corn, canola, sunflower and soybean have been analyzed for their composition. 相似文献
A novel method, epoxidation/reduction of vegetable oils, is developed to prepare bio‐based polyols for the manufacture of polyurethanes (PUs). These polyols are synthesized from castor oil (CO), epoxidized soybean oil, and epoxidized linseed oil and their molecular structures are characterized. They are used to prepare a variety of PUs, and their thermomechanical properties are compared to those of PU made with petroleum‐based polyol (P‐450). It is shown that PUs made with polyols from soybean and linseed oil exhibit higher glass transition temperatures, tensile strength, and Young's modulus and PU made with polyol from CO exhibits higher elongation at break and toughness than PU made with P‐450. However, PU made with P‐450 displays better thermal resistance because of tri‐ester structure and terminal functional groups. The method provides a versatile way to prepare bio‐polyols from vegetable oils, and it is expected to partially or completely replace petroleum‐based polyols in PUs manufacture.
Here are reported composites made by crosslinking unsaturated units in canola, sunflower, or linseed oil with sulfur to yield CanS , SunS , and LinS , respectively. These plant oils were selected because the average number of crosslinkable unsaturated units per triglyceride vary from 1.3 for canola to 1.5 for sunflower and 1.8 for linseed oil. The remeltable composites show compressive strengths that increase with increasing unsaturation number from CanS (9.3 MPa) to SunS (17.9 MPa) to LinS (22.9 MPa). These values for SunS and LinS are competitive when compared with the value of 17 MPa required for residential building using traditional Portland cement. The plant oil composites are recyclable over many cycles and can retain up to 100% of strength after 24 hr in oxidizing acid under conditions where Portland cement is dissolved in under 30 min. Infusion of the composites into premade cement blocks affords them with significantly improved acid resistance as well. This work thus provides a simple, nearly 100% atom economical route to convert plant oils and waste sulfur to composites having enhanced performance over commercial structural materials. 相似文献
The restriction to the use of synthetic antioxidants has fostered the research on natural antioxidants, taking into account that the prolonged usage of these substances can harm seriously the human being provoking degenerative diseases. In the present study, the antioxidant effect of the ethanolic rosemary (Rosmarinus officinalis L.) extract on the oxidative stability of edible vegetable oils was investigated by means of the pressurized differential scanning calorimetry (PDSC) and oven test techniques. The rosemary extract, at the concentration of 2,000 mg kg?1, as well as the synthetic antioxidant tert-butylhydroquinone (TBHQ) at the concentrations of 100 and 200 mg kg?1 were added to samples of sunflower oil, corn oil, and soybean oil. The fatty acid profiles of the vegetable oils were determined by gas chromatography–mass spectrometry confirming the elevated contents of unsaturated fatty acids. The thermogravimetric analysis showed that the rosemary extract is stable at the frying temperature of the oils. The results of the oxidative stability demonstrated that the extract of Rosmarinus officinalis displayed a more effective protective action in the PDSC technique, when compared with the synthetic antioxidant TBHQ, indicating that it is a promising source of natural antioxidants for edible vegetable oils. 相似文献
This work presents a study of the thermal decomposition of commercial vegetable oils and of some of their thermal properties
by termogravimetry (TG), derivative termogravimetry (DTG) and by differential thermal analysis (DTA). Canola, sunflower, corn,
olive and soybean oils were studied. A simultaneous SDT 2960 TG/DTA from TA Instruments was used, with a heating rate of 10
K min-1 from 30 to 700°C. A flow of 100 mL min-1 of air as the purge gas was used in order to burnout the oils during analysis to estimate their heat of combustion. From
the extrapolated decomposition onset temperatures obtained from TG curves, it can be seen that corn oil presents the highest
thermal stability (306°C), followed by the sunflower one (304°C). Olive oil presents the lowest one (288°C). The heat of combustion
of each oil was estimated from DTA curves, showing the highest value for the olive oil. Except for corn oil, which presents
a significantly different thermal decomposition behavior than the other oils, a perfect linear correlation is observed, with
negative slope, between the heat of combustion of an oil and its respective extrapolated onset temperature of decomposition
in air.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
The digestion rates of microalgal (docosahexaenoic acid, DHA, 56.8%; palmitic acid, 22.4%), fish (DHA, 10.8%; eicosapentaenoic acid, EPA, 16.2%), and soybean oils (oleic, 21.7%; linoleic acid, 54.6%) were compared by coupling the in vitro multi-step and in vivo apparent digestion models using mice. The in vitro digestion rate estimated based on the released free fatty acids content was remarkably higher in soybean and fish oils than in microalgal oil in 30 min; however, microalgal and fish oils had similar digestion rates at longer digestion. The in vivo digestibility of microalgal oil (91.49%) was lower than those of soybean (96.50%) and fish oils (96.99%). Among the constituent fatty acids of the diet oils, docosapentaenoic acid (DPA) exhibited the highest digestibility, followed by EPA, DHA, palmitoleic, oleic, palmitic, and stearic acid, demonstrating increased digestibility with reduced chain length and increased unsaturation degree of fatty acid. The diet oils affected the deposition of fatty acids in mouse tissues, and DHA concentrations were high in epididymal fat, liver, and brain of mice fed microalgal oil. In the present study, microalgal oil showed lower in vitro and in vivo digestibility, despite adequate DHA incorporation into major mouse organs, such as the brain and liver. 相似文献
Castor oil was initially subjected to an interesterification reaction with linseed and tung oils and the resulting intermediate was used for the preparation of polyurethanes and their IPNs with poly(methyl methacrylate). They were characterized for their physico-mechanical, swelling, and thermal properties. The morphologies of IPNs were studied with the aid of scanning electron microscopy and differential scanning calorimetry. On comparing the mechanical properties of castor oil polyurethane (CU) and their IPNs (C-IPNs) with those of the castor oil modified with linseed and tung oil (L-IPN and T-IPN, respectively) it was found that L-IPNs showed higher tensile strength, hardness, and better compatibility than C-IPNs. All IPNs showed synergistic effect in elongation and exhibited similar thermal behavior with no significant change with respect to their composition. However, the castor oil polyurethane and their IPNs showed relatively higher elongation and better resistance to solvents. 相似文献
Edible oils are used in the preparation of foods as a part of their recipe or for frying. So to ensure of food safety, checking the quality of the oils before and after usage is an important subject in food control laboratories. In this study, edible oils from four different sources (canola, corn, sunflower and frying) were heated for 36 h at 170 °C and sampling was done every 6 h. The free fatty acid, peroxide value and the content of some fatty acids (C16:0, C18:0, C18:1, C18:2, C18:3) of the oil samples were determined by standard methods. Then, the ATR-FTIR spectra of the samples were collected. The partial least squares (PLS) regression combined with genetic algorithm was performed on the spectroscopic data to obtain the appropriate predictive models for the simultaneous estimation of acid value, peroxide value and the percentage of five kinds of fatty acids. The effect of some preprocessing methods on these models was also investigated. Preprocessing of data by orthogonal signal correction (OSC) resulted in the best predictive models for all oil properties. The correlation coefficients of calibration set (>0.99) and validation set (>0.86 and in most case >0.94) of the OSC–PLS model suggested suitable predictive modeling for all studied parameters in the oil samples. This method could be suggested as a rapid, economical and environmental friendly technique for simultaneous determination of seven noted parameters in the edible oils. 相似文献
The fatty acid profiles of frequently consumed oils and crops cultivated in Turkey were investigated in regard to omega fatty
acids. Analyses were carried out on commercially sold oils, sunflower, olive, and fish oils, and oils extracted from fatty
seeds of hazelnut, walnut, olive, sunflower, poppy, sesame, and pumpkin, and butter produced in Turkey. Hazelnut and olive
oils were found to be rich in omega-9 (oleic acid 18:1), walnut, poppy seed, sesame, and pumpkin seed were rich in omega-6
(linoleic acid 18:2), and butter was rich in short chain fatty acids and omega-9. Fish oil, from mackerel, was the richest
in omega-3 fatty acids and fatty acid diversity. There were some alterations between commercially sold oils and oils extracted
from seeds in regard to fatty acid percentages and variety. 相似文献