Thermo Oxidative Degradation Behavior of Jatropha Curcass L. Oil in the Presence of Antioxidant

2013 ◽  
Vol 393 ◽  
pp. 893-898
Author(s):  
Abdul Munir Hidayat Syah Lubis ◽  
Bambang Ari-Wahjoedi ◽  
Mustafar Sudin ◽  
Parman Setyamartana
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Oxidative Degradation ◽  
Gravimetric Analysis ◽  
Jatropha Oil ◽  
Base Oil ◽  
Long Time ◽  
First Onset ◽  
Lower Temperature ◽  
Oxidative Behavior ◽  
Thermo Oxidative Degradation

Seed oils were used as base oil since long time ago. However their usage is limited due to its thermo oxidative and cold flow properties. Chemical modification and addition of proper additives are known to be able to improve these limitations. In this work, the effect of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as potential hindered phenol antioxidant (HPAO) on thermo-oxidative degradation of jatropha oil was investigated. 1, 3, 5 wt% of antioxidant was dissolved into jatropha oil and their thermo-oxidative behavior was studied by using thermo-gravimetric analysis method under oxidative environment. The addition of the HPAO was found to accelerate the occurrence of thermal degradation first onset of jatropha oil. This factor corresponds to reaction of the compound during heating that reduces the peroxides formation to a less-reactive alcohol which is more volatile, thus making the first onset temperature occurred at a lower temperature.

Vegetable Oils as Base Oil for Industrial Lubricants: Evaluation Oxidative and Low Temperature Properties Using TGA, DTA and DSC

2005 ◽  
Author(s):  
N. H. Jayadas ◽  
K. Prabhakaran Nair ◽  
G. Ajithkumar
Keyword(s):  
Low Temperature ◽  
Vegetable Oils ◽  
Thermo Gravimetric Analysis ◽  
Oxidative Degradation ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Thermal Stabilities ◽  
Base Oil ◽  
Base Oils

In this paper oxidative degradation of saturated and unsaturated vegetable oils is studied by thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) and their low temperature properties are studied by differential scanning calorimetry (DSC). Both non-isothermal and isothermal thermo gravimetric analysis procedures are used for the study. The onset temperatures of oxidative degradation and weight gain in isothermal TGA are taken as measures of oxidative and thermal stabilities. Three vegetable oils namely coconut oil, sesame oil and sunflower oil with varying degree of un-saturation are selected for the study. The results are found to agree with reported results obtained by conventional methods. Several standard methods are currently available for determining the oxidative and low temperature properties of base oils. These methods are extremely time-consuming and data reproducibility between laboratories is poor. TGA, DTA and DSC are excellent tools to evaluate base oils in respect of their oxidative and low temperature behavior in that they produce results quickly, reproducibly and the sample requirement is very low.

KINETIC MODEL FOR THERMAL DEHYDROCHLORINATION OF CHLORINATED NATURAL RUBBER WITH DIFFERENT CHLORINE CONTENT

2014 ◽  
Vol 87 (2) ◽  
pp. 370-382
Author(s):  
Jing Chen ◽  
Lanzhen He ◽  
Yasheng Chen ◽  
Jieping Zhong ◽  
Canzhong He ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Storage Conditions ◽  
Chlorine Content ◽  
Heating Process ◽  
Lower Temperature ◽  
Novel Model ◽  
Derivative Thermogravimetry ◽  
Selection Of ◽  
Thermo Oxidative Degradation

ABSTRACT A novel model for calculating dehydrochlorination kinetics at a lower temperature of chlorinated natural rubber (CNR) is presented. It has been observed that dehydrochlorination is complex and involves three different stages. A model that accounts for dehydrochlorination at lower temperature is proposed. The kinetic parameters are obtained from dehydrochlorination experiments at 60–90 °C. The results of the kinetic calculation show that the apparent activation energy decreases with an increment of chlorine content. Higher chlorine content CNR makes it easier to remove hydrochloric acid when heated, but its dehydrochlorination rate affected by temperature is significantly less than that of the sample with a lower chlorine content. The thermogravimetric/derivative thermogravimetry results show that the beginning temperature of thermo-oxidative degradation rises with the increment of chlorine content. During the heating process, the higher chlorine content CNR is more stable than the lower one. The results suggest the storage conditions and basis for selection of appropriate temperature for the preparation of CNR from latex.

Kinetic Study of the Thermo-Oxidative Degradation of Squalane (C30H62) Modelling the Base Oil of Engine Lubricants

2009 ◽  
Author(s):  
Moussa Diaby ◽  
Michel Sablier ◽  
Anthony Le Negrate ◽  
Mehdi El Fassi
Keyword(s):  
Oxidative Degradation ◽  
Engine Oil ◽  
Ongoing Research ◽  
Base Oil ◽  
Rate Law ◽  
Tert Butyl ◽  
Oxidation Rates ◽  
Base Oils ◽  
Wide Range ◽  
Thermo Oxidative Degradation

On the basis of ongoing research conducted on the clarification of processes responsible for lubricant degradation in the environment of piston grooves in EGR diesel engines, an experimental investigation was aimed to develop a kinetic model which can be used for the prediction of lubricant oxidative degradation correlated to endurance test conducted on engines. Knowing that base oils are a complex blend of paraffins and naphtenes with a wide range of sizes and structures, their chemistry analysis during the oxidation process can be highly convoluted. In the present work, investigations were carried out with the squalane (C30H62) chosen for its physical and chemical similarities with the lubricant base oils used during the investigations. Thermo-oxidative degradation of this hydrocarbon was conducted at atmospheric pressure in a tubular furnace, while varying temperature and duration of the tests in order to establish an oxidation reaction rate law. The same experimental procedures was applied to squalane doped with two different phenolic antioxidants usually present in engine oil composition: 2,6-di-tert-butyl-4-methylphenol (BHT), and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (OBHP). Thus, the effect of both antioxidants on the oxidation rate law was investigated. Data analysis of the oxidized samples (FTIR spectroscopy, gas chromatography/mass spectrometry GC/MS) allowed to rationalize the thermo-oxidative degradation of squalane. The resulting kinetic modelling provides a practical analytical tool to follow the thermal degradation processes, which can be used for prediction of base oil hydrocarbon ageing. If experiments confirmed the role of phenolic additives as an affective agent to lower oxidation rates, the main results lay in the observation of a threshold temperature where a reversed activity of these additives was observed.

Low Temperature Die Attach Material

1989 ◽  
Vol 167 ◽  
Author(s):  
Mark A. Blocker ◽  
Tom L. Herrington ◽  
My N. Nguyen
Keyword(s):  
Heat Treatment ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Large Area ◽  
Thermo Gravimetric ◽  
Organic System ◽  
Die Attach ◽  
Volatile Organic ◽  
Lower Temperature ◽  
Sintering Characteristics

AbstractA new silver lead phosphovanadate glass die attach material is discussed. Its sintering characteristics are examined by dilatometry and the organic system by thermo gravimetric analysis. Sintering is found to occur at lower temperature than conventional silver glass systems. This is caused by reaction between silver and one of the glass components during heat treatment. The vehicle is found to evaporate faster allowing void free processing for large area dice.The new glass combined with a more volatile organic system has produced a single pass die attach material which can be fired as low as 360°C.

Kinetic Study of the Thermo-Oxidative Degradation of Squalane (C30H62) Modeling the Base Oil of Engine Lubricants

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Moussa Diaby ◽  
Michel Sablier ◽  
Anthony Le Negrate ◽  
Mehdi El Fassi
Keyword(s):  
Oxidative Degradation ◽  
Engine Oil ◽  
Ongoing Research ◽  
Base Oil ◽  
Rate Law ◽  
Tert Butyl ◽  
Oxidation Rates ◽  
Base Oils ◽  
Wide Range ◽  
Thermo Oxidative Degradation

On the basis of ongoing research conducted on the clarification of processes responsible for lubricant degradation in the environment of piston grooves in exhaust gas recirculation (EGR) diesel engines, an experimental investigation was aimed to develop a kinetic model, which can be used for the prediction of lubricant oxidative degradation correlated with endurance test conducted on engines. Knowing that base oils are a complex blend of paraffins and naphthenes with a wide range of sizes and structures, their chemistry analysis during the oxidation process can be highly convoluted. In the present work, investigations were carried out with the squalane (C30H62) chosen for its physical and chemical similarities with the lubricant base oils used during the investigations. Thermo-oxidative degradation of this hydrocarbon was conducted at atmospheric pressure in a tubular furnace, while varying temperature and duration of the tests in order to establish an oxidation reaction rate law. The same experimental procedures were applied to squalane doped with two different phenolic antioxidants usually present in engine oil composition: 2,6-di-tert-butyl-4-methylphenol and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Thus, the effect of both antioxidants on the oxidation rate law was investigated. Data analysis of the oxidized samples (Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry) allowed rationalization of the thermo-oxidative degradation of squalane. The resulting kinetic modeling provides a practical analytical tool to follow the thermal degradation processes, which can be used for prediction of base oil hydrocarbon aging. If experiments confirmed the role of phenolic additives as an effective agent to lower oxidation rates, the main results lie in the observation of a threshold temperature where a reversed activity of these additives was observed.

Quantifying Partially-Carbonated Profiles of Concrete with Low Water/Binder Ratio Exposed to Natural Carbonation

2010 ◽  
Vol 146-147 ◽  
pp. 1811-1814
Author(s):  
Ming Fang Ba ◽  
Chun Xiang Qian
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Small Specimen ◽  
Thermo Gravimetric ◽  
Good Reliability ◽  
Caco3 Content ◽  
Binder Ratio ◽  
Long Time ◽  
Ir Analysis ◽  
Natural Carbonation

Thermo-gravimetric analysis (TGA) and Infrared Spectrum (IR) analysis were adopted to quantify the partially-carbonated profiles of concrete segment exposed to long-time natural carbonation. The results showed that the residual Ca(OH)2 content could be calculated by TGA, and the CaCO3 content formed by carbonation could also be quantified by IR. Thus the partial-carbonation profile illustrated by residual Ca(OH)2 distribution was lower than that by CaCO3 distribution, which indicates Ca(OH)2 and C-S-H gel were carbonated. Furthermore, the carbonation degree of concrete segment was lower than that of specimen because of dimension effect, which suggested that the small specimen could be used to assess carbonation related durability of concrete structures with good reliability.

scholarly journals Physicomechanical and Operational Properties Polyurethane Thermal Panels

2020 ◽  
Vol 9 (4) ◽  
pp. 446-454
Keyword(s):  
Ir Spectroscopy ◽  
Uv Radiation ◽  
Thermo Gravimetric Analysis ◽  
Operation Time ◽  
Heat Stability ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Operational Characteristics ◽  
Lower Temperature ◽  
Thermal Stability Of

Evaluation of consumer properties of polyurethane thermal panels is the goal of the work. Physico-mechanical and operational characteristics of thermal panels are determined to achieve the purpose of the work. Methods of IR spectroscopy and thermo gravimetric analysis were used to study the structure of the samples. Satisfactory consumer properties of the studied thermo panels are brought out: compliance of clinker with the DIN EN 121 standard; absence of visual defects and change of color of thermo panels after 50 cycles of freezing-thawing; absence of changing color of thermo panels after influence of UV of radiation with the wavelength of 240-320 nanometers within 607 hours 30 minutes; high values of coefficients of sound absorption in the frequency range from 600 to 1600 Hz; low heat conductivity of the FPU layer. The influence of UV-radiation on thermal stability of foamed polyurethane is valued. Thermal analysis methods and IR spectroscopy are used to assess the degree of UV - destruction of polyurethane foam. At destruction of foamed polyurethane there is a rupture of chemically weak communication and formation of alcohols, air, olefins. The results of IR-spectroscopy illustrate the beginning of the processes of destruction of samples of FPU under the influence of UV-radiation. Using the thermo gravimetric analysis the research of the FPU thermal properties under the influence of UV - radiations is conducted. It is established that compositions from FPU under the influence of UV- radiation have lower temperature of the beginning of decomposition, than initial material. The influence of UV-radiation on heat stability of the studied compositions is shown. The possible mechanism of destruction of FPU is confirmed in the research. The DSС method has estimated the resistance of FPU to the oxidizing influence characterizing the material operation time. The studied consumer properties of thermal panels show that they can be used in civil engineering as effective protection structures of buildings.

scholarly journals Dehydration of Fructose to 5-HMF over Acidic TiO2 Catalysts

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1178 ◽  
Author(s):  
Maria Luisa Testa ◽  
Gianmarco Miroddi ◽  
Marco Russo ◽  
Valeria La Parola ◽  
Giuseppe Marcì
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Process Condition ◽  
Textural Properties ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Catalytic Sites ◽  
Lower Temperature

Different solid sulfonic titania-based catalysts were investigated for the hydrothermal dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The catalytic behavior of the materials was evaluated in terms of fructose conversion and selectivity to 5-HMF. The surface and structural properties of the catalysts were investigated by means of X-ray diffraction (XRD), N2 adsorption isotherms, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and acid capacity measurements. Special attention was focused on the reaction conditions, both in terms of 5-HMF selectivity and the sustainability of the process, choosing water as the solvent. Among the various process condition studied, TiO2-SO3H catalyzed a complete conversion (99%) of 1.1M fructose and 5-HMF selectivity (50%) and yield (50%) at 165 °C. An important improvement of the HMF selectivity (71%) was achieved when the reaction was carried out by using a lower fructose concentration (0.1M) and lower temperature (140 °C). The catalytic activities of the materials were related to their acid capacities as much as their textural properties. In particular, a counterbalance between the acidity and the structure of the pores in which the catalytic sites are located, results in the key issue for switch the selectivity towards the achievement of 5-HMF.

Preparation and performance evaluation of mPAO8 using olefin from coal as raw material

2017 ◽  
Vol 69 (5) ◽  
pp. 678-682 ◽  
Author(s):  
Yuefeng Ma ◽  
Jian Xu ◽  
Xiangqiong Zeng ◽  
Haizhen Jiang ◽  
Jiusheng Li
Keyword(s):  
Thermal Stability ◽  
Oxidative Stability ◽  
Thermo Gravimetric Analysis ◽  
Viscosity Index ◽  
Oxidation Stability ◽  
Molecular Structures ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Content Type ◽  
Base Oil

Purpose The purpose of this paper is to prepare metallocene polyalphaolefin 8 (mPAO8) by the oligomerization of olefin from coal with metallocene catalyst system and compare it with commercially available polyalphaolefin 8 (PAO8) from Chevron. Design/methodology/approach Molecular structures, component and mass were determined by nuclear magnetic resonance spectroscopy, gas chromatography and gel permeation chromatography, respectively. The physico-chemical properties, including Noack volatility, viscosity index and elemental analyses, were studied. The oxidative stability was evaluated by pressurized differential scanning calorimetry, whereas the thermal stability was studied by thermo-gravimetric analysis. Findings The produced mPAO8 consisted of a large part of tetramer, pentamer and a small part of trimer and hexamer. Additive T501 significantly improved the oxidation stability of PAO8 from Chevron and the synthesized mPAO8. Both samples had similar properties, such as oxidative stability, additive response, pour point and Noack volatility loss. But mPAO8 possessed a higher thermal stability, better viscosity index and flash point than PAO8. Therefore, the mPAO8 prepared by the oligomerization of olefin from coal could be used as base oil for lubricant development. Originality/value The mPAO8 base oil was successfully prepared by successive carbon numbers and shows similar properties with commercially available PAO8 products from Chevron. The findings can cover the shortage of the synthesis lubricants market in China.

Properties of camphor oil/poly (methyl methacrylate) composites and their application on cotton fabrics

2016 ◽  
Vol 87 (11) ◽  
pp. 1318-1325
Author(s):  
Chunxia Wang ◽  
Min Li ◽  
Liping Zhang ◽  
Shaohai Fu ◽  
Chaoxia Wang
Keyword(s):  
Methyl Methacrylate ◽  
Thermo Gravimetric Analysis ◽  
Miniemulsion Polymerization ◽  
Cotton Fabrics ◽  
Gravimetric Analysis ◽  
Mosquito Repellent ◽  
Poly Methyl Methacrylate ◽  
Transmission Electron ◽  
Long Time ◽  
Camphor Oil

Camphor oil/poly (methyl methacrylate) (PMMA) composites were prepared by the miniemulsion polymerization method, and characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and thermo-gravimetric analysis. The results indicated that based on the weight of camphor oil/PMMA composites, the amount of 18% camphor oils was encapsulated by the PMMA; the dispersion of the prepared composites showed excellent stability to temperature in the range of 20–60℃. Application properties of camphor oil/PMMA composites, such as sustained release, antibacterial and mosquito repellent performance, were further investigated. The results indicated that the PMMA covering can effectively reduce the release rate of camphor oil. The antibacterial rates for E. coli and S. aureus were 67.21% and 41.59%, respectively, and the “landing time” for the first mosquito was about 144.9 min when the cotton fabrics were coated eight times. The coated cotton fabrics can retain the antibacterial and mosquito repellent performance for a long time, even after multiple washings.

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