Amine-functionalized magnetic nanoparticles NiFe2O4@SiO2@Amine (AMNP), and epoxy functionalized magnetic nanoparticles, CuFe2O4@SiO2@Epoxy (EMNP) were synthesized in three steps. Homogeneous stable dispersion of AMNP and EMNP, at concentrations of 1, 5, 10, 15, 20 wt% in epoxy resin were prepared using stoichiometric amounts of 4,4’-diaminodiphenylsulfone (DDS) as a curing. The optimum ratio of AMNP and EMNP were found to be 5%, and these were investigated by the total enthalpy of the curing reaction using differential scanning calorimetry (DSC) thermograms at 10°C/min. The cure kinetics of epoxy resin-functional magnetic nanoparticles-DDS composites were studied using non-isothermal DSC thermograms at different heating rates (5, 10, 15, 20°C/min). The kinetic parameters of the curing process, such as activation energy ( Ea), pre-exponential factor ( A), and rate constant ( k) were determined using several non-isothermal kinetic methods: Kissinger-Akahira-Sunose (KAS), Kissinger, Straink, Flynn-Wall-Ozawa (OFW), and Bosewell. The kinetic curing values obtained with different kinetic methods are well-matched. The Ea values were calculated in the range of 59.80 to 65.94, 57.69 to 63.92, and 45.38 to 52.45 kJ.mol−1 for the DGEBA/DDS, DGEBA/DDS/AMNP, and DGEBA/DDS/EMNP systems respectively. Also, The A values, using the Kissinger method, were calculated to be in the range of 7.0 × 105, 4.0 × 105, and 0.2 × 105 S−1 for the DGEBA/DDS, DGEBA/DDS/AMNP, and DGEBA/DDS/EMNP systems respectively. The glass transition temperatures of cured resins were determined with DSC, and the surface morphology of the nanocomposites and also the dispersion of the nanoparticles were investigated using scanning electron microscopy (SEM).
UDC 547.913 Hydrodistilled volatile oils from crushed dry stems, leaves, and roots of Prangos latiloba Korov. (Umbelliferae) growing wild in Sabzevar (Iran) were analyzed by GC and GC/MS. Eight compounds constituting 84.72% of stem oil, twelve compounds constituting 95.39% of leaf oil, and nine compounds constituting 88.73% of root oil have been identified. The main components of stem oil were γ-cadinene (30.39%), α-pinene (25.47%), and sabinene (12.55%). The main components of leaf oil were germacrene D (27.79%), α-pinene (17.81%), β-caryophyllene (12.75%), and β-pinene (11.23%). The main components of root oil were spathulenol (29.5%), 1,8-cineol (19.42%), p-cymene (17.03%), and α-bisabolol (15.33%). The genus Prangos consists of about 30 species [1]. In Iran, fifteen species of this Umbelliferae family plant exist, among which five are endemic [2]. Medicinal applications have been reported for some Prangos species as: emollient, carminative [3], antifungal [4], antioxidant [5], antibacterial, cytokine release inhibitor [6], and anti-HIV [7]. Investigation of chemical components of the genus Prangos has resulted in isolation and identification of terpenoids [8-15], flavonoids [5], coumarins, and glycosides [6].In this work, hydrodistilled volatile oils from crushed dry stems, leaves, and roots of Prangos latiloba Korov. (Umbelliferae) from Sabzevar (Iran), were studied by GC and GC/MS. The air-dried stems, leaves, and roots of the plant yielded 0.18, 0.25, and 0.38% (w/w) oil, respectively. The oil of leaves and stems is clear yellowish and that of roots is dark yellow. Eight components were identified in the stem oil, which contains 84.72% of the compounds. Twelve components were identified in the leaves, which contain 95.39% of the compounds. Nine components were also identified in the roots, which contain 88.73% of the compounds. Table 1 presents the list of compounds identified in the oils. As can be seen, the main components which were characterized in the stems are γ-cadinene (30.39%), α-pinene (25.47%), and sabinene (12.55%). The main components in the leaves were germacrene D (27.79%), α-pinene (17.81%), β-caryophyllene (12.75%), and β-pinene (11.23%), and in the roots they were spathulenol (29.5%), 1,8-cineol (19.42%), p-cymene (17.03%), and α-bisabolol (15.33%).The oil composition of some Prangos species has been the subject of several investigations [9][10][11][12][13][14][15][16][17][18]. A comparison of the chemical composition of Prangos latiloba Korov. with previous studies on volatile oils of other species showed variation of the major components. α-Pinene is the main constituent of oils of fruits of P. uloptera (41.9%) and P. ferulacea (16.7%) [13][14][15]. The previous study on volatile oils of leaves and stems of P. latiloba [14] showed that the main constituents are α-pinene (25.1%), limonene (16.1%), and myrcene (9.51%). However, according to the results of our study on volatile oils of stems, leaves, and roots, γ-cadinene (30.39%), spathulenol (29.5%), germacrene D (27.79%), and α-pinene (...
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