Dielectric analysis of vegetable and mineral oils

Author(s):  
Jiri Ulrych ◽  
Michal Svoboda ◽  
Radek Polansky ◽  
Josef Pihera
Author(s):  
Madhubhushan M ◽  
Seshaiah S ◽  
Chandrudu J ◽  
Sagar R ◽  
Akila CR

The common watermelon item (Citrullus lanatus) seeds were gained from castoffs verdant nourishments for use by decorating, sun ventilation and pulverizing. Light yellow-toned oil was gotten by dissolvable withdrawal using oil atmosphere and the going with traits were gotten using oil ether: pH, refractive rundown, thickness, dissolvable miscibility, coagulating temperature, fire nature, express gravity, streak point and warmth of consuming. With a shallow level of unsaturation, stepped level of smoothness, and proximity of raised degree of the sensible proportion of free unsaturated fats. The low assessment of the solidifying temperature of the oil offered a hint that the oil can be managed in various areas paying little heed to the qualification in temperature. The following level of linoleic destructive of the oil offers a hint of natural gradation of solidarity. Fatty esters are increasing expanding significance as a biodegradable swap for mineral oils. In some request regions, for example, cutting tool oil, gearbox, pressure-driven oils, and greases for raw petroleum creation, the oleochemical items are set up. Nonetheless, certain particular wellsprings of fatty esters are hitherto to be abused for this comparative reason. This exploration subsequently tests into one of the less used wellsprings of fatty esters in watermelon. The oil from the kernels demonstrations a top-notch yield presents significant utilitarian gatherings for change and thus was utilized to set up an assortment of oleochemicals which demonstrated excellence materials in contrast with the routinely utilized oils feed frameworks for oleochemicals after portrayal. The photopolymers acquired indicated piercing vinyl protons for consistent polymerize.


Author(s):  
O. V. Grebeneva ◽  
A. Z. Shadetova ◽  
M. V. Rusyaev

The coefficients of danger to health of 84 workers of 4 lowering stations of the power enterprise from inhalation influence of pollutants of motor transport are calculated: nitrogen dioxide, dust, aerosols of mineral oils and hydrocarbons. The risk of combined effects of chemicals on the target organs was determined by an increase in the chance of respiratory diseases by 1.77 times.


2017 ◽  
pp. 91-95
Author(s):  
E. I. Grushova ◽  
A. .. Al Razuqi ◽  
E. S. Chaiko ◽  
O. A. Miloserdova

IR spectroscopy investigated structural and group composition of base mineral oils isolated from the vacuum distillate by selective purification of N-methylpyrrolidone and the low temperature dewaxing in the presence of a solvent. The role of the latter was carried out by the systems acetone - toluene, acetone - methyl tertiary butyl ether, methyl ethyl ketone - toluene, acetone - toluene - modifying additive. It was shown that the chemical composition of the group of base oils and slack waxes is defined as the nature of the solvent to the dewaxing, and oils sequence of purification steps.


2018 ◽  
Vol 68 (12) ◽  
pp. 2881-2885
Author(s):  
Iosif Lingvay ◽  
Gabriela Oprina ◽  
Livia Carmen Ungureanu ◽  
Alexandra Pica ◽  
Valerica Stanoi

The behaviour of copper and insulation paper in various electrical insulating fluids (transformer oils) exposed to thermal ageing at 110�30C for 1000 hours in closed vessels (without access to atmospheric oxygen) has been studied. The processing of the comparative experimental data revealed in all cases that the concentration of dissolved oxygen in the investigated oils decreases exponentially during the heat treatment. In the presence of the copper foil, the oxygen is almost depleted (the dissolved oxygen concentration is approaching zero), indicating a higher affinity of the copper to oxygen than the affinity to oxygen of the investigated oils. In the presence of the copper foil and / or of the insulation paper, the degradation processes of the mineral oils have a pronounced character, explained by the catalytic activity of the Cu2O film that has been formed and by the paper degradation, respectively. A high thermo-oxidative stability was noticed in the case of natural triglyceride oils, particularly for the synthetic ester-based oil.


2018 ◽  
Vol 69 (9) ◽  
pp. 2366-2371
Author(s):  
Andrei Cucos ◽  
Petru Budrugeac ◽  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Andreea Voina

Thermal TG/DTG/DTA analysis coupled with FTIR spectroscopy was applied to some sorts of mineral and vegetable oils used in electrical equipment. On heating in inert atmosphere, it was observed that the mineral oils vaporize, while the vegetable oils undergo hydrolysis, yielding fatty acids as main volatiles, as indicated by FTIR. In synthetic air, the FTIR spectra of gaseous products confirm the presence of similar oxidation products, both for mineral and vegetable oils. The TG results indicated that the vegetable-based oils exhibit a substantially higher thermal stability than the mineral oils. The presence or absence of anti-oxidant inhibitors in these oils greatly influences the onset of the oxidation process in air environment factor, as results from the DTA results.


1952 ◽  
Vol 6 ◽  
pp. 476-482 ◽  
Author(s):  
C. Boelhouwer ◽  
A.J. van Riemsdijk ◽  
J. van Steenis ◽  
H.I. Waterman

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1734
Author(s):  
Erick Franieck ◽  
Martin Fleischmann ◽  
Ole Hölck ◽  
Larysa Kutuzova ◽  
Andreas Kandelbauer

We report on the cure characterization, based on inline monitoring of the dielectric parameters, of a commercially available epoxy phenol resin molding compound with a high glass transition temperature (>195 °C), which is suitable for the direct packaging of electronic components. The resin was cured under isothermal temperatures close to general process conditions (165–185 °C). The material conversion was determined by measuring the ion viscosity. The change of the ion viscosity as a function of time and temperature was used to characterize the cross-linking behavior, following two separate approaches (model based and isoconversional). The determined kinetic parameters are in good agreement with those reported in the literature for EMCs and lead to accurate cure predictions under process-near conditions. Furthermore, the kinetic models based on dielectric analysis (DEA) were compared with standard offline differential scanning calorimetry (DSC) models, which were based on dynamic measurements. Many of the determined kinetic parameters had similar values for the different approaches. Major deviations were found for the parameters linked to the end of the reaction where vitrification phenomena occur under process-related conditions. The glass transition temperature of the inline molded parts was determined via thermomechanical analysis (TMA) to confirm the vitrification effect. The similarities and differences between the resulting kinetics models of the two different measurement techniques are presented and it is shown how dielectric analysis can be of high relevance for the characterization of the curing reaction under conditions close to series production.


Sign in / Sign up

Export Citation Format

Share Document