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1.
Several fatty derivatives with bulky moieties were prepared by treatment of epoxidized isopropyl oleate with a number of alcohols
in the presence of sulfuric acid catalyst to provide a series of α-hydroxy ethers in good yield. The materials were analyzed
for cold flow performance through cloud point and pour point determinations. The most promising α-hydroxy ether produced in
this study, with respect to both low temperature behavior and economic criteria, was isopropyl 9(10)-(2-ethylhexoxy) 10(9)-hydroxystearate,
which has a cloud point of −23°C and pour point of −24°C. 相似文献
2.
New epoxidized soybean oil (ESO)/clay nanocomposites have been prepared with triethylenetetramine (TETA) as a curing agent. The dispersion of the clay layers is investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM data reveal the intercalated structure of ESO/clay nanocomposites has been developed. The thermogravimetric analysis exhibits that the ESO/clay nanocomposites are thermally stable at temperatures lower than 180 °C, with the maximum weight loss rate after 325 °C. The glass transition temperature, Tg, about 7.5 °C measured by differential scanning calorimetry (DSC) and Tg about 20 °C measured by dynamic mechanical study have been obtained. The difference in the Tg between DSC and dynamic measurements may be caused by different heating rate. The nanocomposites with 5-10 wt% clay content possess storage modulus ranging from 2.0×106 to 2.70×106 Pa at 30 °C. The Young's modulus (E) of these materials varies from 1.20 to 3.64 MPa with clay content ranging from 0 to 10 wt%. The ratio of epoxy (ESO) to hydrogen (amino group of TETA) greatly affects dynamic and tensile mechanical properties. At higher amount of TETA, the nanocomposites exhibit stronger tensile and dynamic properties. 相似文献
3.
In this study, polyvinyl alcohol/organically modified montmorillonite (HDA/MMT; organoclay) composite was prepared for the intercalation processes. Firstly, the rheological behavior of aqueous montmorillonite dispersions was investigated as a function of solid content. Hexadecylamine (HDA) was added to the montmorillonite dispersion (2%, w/w) in different concentrations in the range of 5 × 10?4 – 9 × 10?3 mmol/L. The basal spacing of the organoclay (OMMT) was studied by X‐ray diffraction. The FTIR spectra are obtained from the modified montmorillonite products, which revealed the characteristic absorbencies after treatment with HDA. HDA/MMT/PVA composite, which was produced by the reaction of 1 wt % PVA solution with organoclay complex, is characterized by the rheology, electrokinetic, XRD, FTIR, and SEM techniques. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2315–2323, 2006 相似文献
4.
5.
Ayse Erol Elif Akalin Fahrettin Sarcan Omer Donmez Sevim Akyuz Cetin M Arikan Janne Puustinen Mircea Guina 《Nanoscale research letters》2012,7(1):656
The excitation energy-dependent nature of Raman scattering spectrum, vibration, electronic or both, has been studied using different excitation sources on as-grown and annealed n- and p-type modulation-doped Ga1 − xInxNyAs1 − y/GaAs quantum well structures. The samples were grown by molecular beam technique with different N concentrations (y = 0%, 0.9%, 1.2%, 1.7%) at the same In concentration of 32%. Micro-Raman measurements have been carried out using 532 and 758 nm lines of diode lasers, and the 1064 nm line of the Nd-YAG laser has been used for Fourier transform-Raman scattering measurements. Raman scattering measurements with different excitation sources have revealed that the excitation energy is the decisive mechanism on the nature of the Raman scattering spectrum. When the excitation energy is close to the electronic band gap energy of any constituent semiconductor materials in the sample, electronic transition dominates the spectrum, leading to a very broad peak. In the condition that the excitation energy is much higher than the band gap energy, only vibrational modes contribute to the Raman scattering spectrum of the samples. Line shapes of the Raman scattering spectrum with the 785 and 1064 nm lines of lasers have been observed to be very broad peaks, whose absolute peak energy values are in good agreement with the ones obtained from photoluminescence measurements. On the other hand, Raman scattering spectrum with the 532 nm line has exhibited only vibrational modes. As a complementary tool of Raman scattering measurements with the excitation source of 532 nm, which shows weak vibrational transitions, attenuated total reflectance infrared spectroscopy has been also carried out. The results exhibited that the nature of the Raman scattering spectrum is strongly excitation energy-dependent, and with suitable excitation energy, electronic and/or vibrational transitions can be investigated. 相似文献
6.
Mehmet Aydın Hüseyin Sevgili Bekir Tufan Yilmaz Emre Sevim Köse 《International Journal of Food Science & Technology》2011,46(3):500-508
Proximate composition and fatty acid (FA) profile of three commercial sea cucumbers; Holothuria tubulosa, Holothuria polii and Holothuria mammata caught from Aegean Sea of Turkey were analysed. The effects of regional variation and drying process on FA composition were also investigated. Moisture, protein, fat and ash contents of the species ranged between 81.24% and 85.24%, 7.88% and 8.82%, 0.09% and 0.18%, and 5.13% and 7.85%, respectively, with a significant changes among species (P < 0.05) with some exceptions. Although FA values varied significantly (P < 0.05) among species and regions, the changes for most FA types representing the same region for different species were not significantly different. Total polyunsaturated fatty acids (PUFA) were found to be higher than total saturated (SFA) and monosaturated FAs (MUFA) accounting for 53.0–62.12% for ∑PUFA, 13.28–16.41% for ∑MUFA and 13.99–19.21% for ∑SFA. While some individual SFAs and PUFAs decreased after drying process, various individual FAs of MUFA increased in their amounts (P < 0.05). Among PUFAs, the highest mean value of eicosapentaenoic acid and docosahexaenoic acid for all regions were determined for H. polii as 7.25% and H. tubulosa as 12.37% in fresh samples, respectively. This study represents new information relating to FA contents and drying effect on FA profile for these species. 相似文献
7.
Hong-Sik?Hwang Atanu?Adhvaryu Sevim?Z.?ErhanEmail author 《Journal of the American Oil Chemists' Society》2003,80(8):811-815
Synthetic lubricant basestocks were prepared from epoxidized soybean oil (ESO) and 2-ethylhexanol (2-EH) to be used alone
or with polyalphaolefin (PAO). Sulfuric acid-catalyzed reaction of ESO with 2-EH involves a ring-opening reaction at the epoxy
group followed by transesterification at the ester group. Reaction with other catalysts including p-toluenesulfonic acid, Dowex 50W-8X, boron trifluoride, and sodium methoxide was also examined. Pour points of the products
were observed as lows as −21 and −30°C without and with 1% of pour point depressant, respectively. When the hydroxy groups
in the products were esterified with an acid anhydride, lower pour points were observed. Pour point depression of the product
by adding PAO has been tested. Oxidative stability of the product was examined using pressurized DSC and compared with those
of synthetic lubricant basestocks, PAO, and a synthetic ester. 相似文献
8.
Jingyuan Xu Zengshe Liu Sevim Z. Erhan 《Journal of the American Oil Chemists' Society》2008,85(3):285-290
Hydrogels formed from biopolymers or natural sources have special advantages because they may have biodegradable and biocompatible
properties. The viscoelastic properties of a newly developed biological hydrogel made from epoxidized soybean oil (ESO) were
investigated. The material called HPESO is a hydrolytic product of polymerized ESO (PESO). HPESO exhibited viscoelastic solid
or gel behavior above 2% (wt. %) concentration at room temperature and viscous liquid behavior at 55 °C. The thermal assembly
disassembly reassembly function of the HPESO hydrogel was completely reversible. The viscoelastic properties of HPESO were
dependent on concentration. Analysis of modulus and concentration dependence and stress relaxation measurement indicated that
HPESO was a physical gel where the cross-linkers between the molecules were physical junctions. HPESO hydrogel also exhibited
fast initial recovery of its viscoelastic properties after being subjected to mechanical shear disruption. The function and
behavior of the HPESO hydrogel suggest that this biomaterial may be suitable for applications in drug delivery and scaffolds
of bioengineering and tissue engineering.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may
also be suitable. 相似文献
9.
轮胎制造行业大量使用各种纤维帘线,然而纤维帘线的设计、开发和制造是一个非常复杂的过程,工程技术人员通常要开展一系列严谨而且复杂的工作,如建立模型、数据分析、结构设计、样品试制和产品测试等,采取不同的方法和技术措施解决过程中存在的各种问题,最后才能确定帘线制造的最佳方案.有限元分析是解决这种具有挑战性工程技术问题最有效的方法之一.尤其是近年来计算能力和智能工具技术水平的快速发展,促进了有限元分析技术的推广应用. 相似文献
10.
Ibrahim Sevim Fatih Hayat Yakup Kaya Nizamettin Kahraman Sadettin Şahin 《The International Journal of Advanced Manufacturing Technology》2013,66(9-12):1825-1834
In this article, Metal Inert Gas (MIG) weldability of commercially received and aged samples of 6061-T6 and 7075-T651 aluminum alloys was investigated. The welding joints were prepared in ten different combinations. Microstructure, microhardness, EDX, energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analyses were used in order to evaluate the effect of aged heat treatment on the performance of welded joints. In addition, the mechanical properties of welding joints were characterized using the tensile and microhardness tests. In conclusion, it was shown that prewelding aging heat treatment improves the mechanical properties of welding joints. 相似文献