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Azhari Muhammad Syam - One of the best experts on this subject based on the ideXlab platform.

  • application of response surface methodology rsm for optimizing the palm based Pentaerythritol ester synthesis
    Industrial Crops and Products, 2014
    Co-Authors: Nur Atiqah Mohamad Aziz, Robiah Yunus, Umer Rashid, Azhari Muhammad Syam
    Abstract:

    Abstract The present study was performed to optimize reaction parameters for the transesterification reaction of palm oil methyl ester and Pentaerythritol by using response surface methodology (RSM). The affecting parameters were selected as temperature (140–190 °C), amount of catalyst (0.5–1.5 wt%), palm oil methyl ester-to-Pentaerythritol molar ratio (4:1–5:1) and reaction time (1–5 h), in order to produce Pentaerythritol ester (tetraester). The optimum operating conditions; temperature at 158 °C; amount of catalyst, 1.19 wt%; molar ratio, 4.5 and 1 h of reaction time were obtained with the result of the Pentaerythritol ester's yield of 40.13%. The interaction parameter of the catalyst amount with the palm oil methyl ester-to-Pentaerythritol molar ratio was found to be the most significant amongst all of the interaction parameters. The Pentaerythritol ester properties were analyzed and compared with the commercial oven chain lubricant. The results indicated that the Pentaerythritol ester is able to withstand a high temperature environment with a flash point of 302 °C and viscosity of 12.7 cSt at 100 °C.

Zhigang Liu - One of the best experts on this subject based on the ideXlab platform.

  • Absorption of isobutane in three linear chained Pentaerythritol esters between 293.15 and 348.15 K
    International Journal of Refrigeration, 2017
    Co-Authors: Yanjun Sun, Xiaopo Wang, Liwen Jin, Dongbo Wang, Zhigang Liu
    Abstract:

    Abstract Isobutane (R600a) is widely used in small capacity refrigeration equipment, especially domestic refrigerator. Knowledge of refrigerant absorption in lubricant oil is one of the essential factors for designing refrigeration system and choosing suitable oil. In this work, the liquid mole fractions of R600a in three linear chained Pentaerythritol esters (Pentaerythritol tetrabutyrate, Pentaerythritol tetrahexanoate, and Pentaerythritol tetraoctanoate) were measured from 293.15 K to 348.15 K by means of isochoric saturation method. The measured data were modeled using the PR EOS and HVOS mixing rule combined with Wilson excess free-energy model. Average relative deviations between the calculated pressure from the model and measured results for R600a + Pentaerythritol tetrabutyrate, R600a + Pentaerythritol tetrahexanoate, and R600a + Pentaerythritol tetraoctanoate systems were 0.74%, 0.90%, and 0.57%, respectively. Maximum relative deviations were 2.13%, 2.91%, and 2.13%, respectively.

  • Phase Equilibrium Behavior for Methoxymethane + Pentaerythritol Tetraheptanoate and Methoxymethane + Pentaerythritol Tetranonanoate Systems
    Journal of Chemical & Engineering Data, 2016
    Co-Authors: Yanjun Sun, Xiaopo Wang, Hanxiao Lang, Liwen Jin, Zhigang Liu
    Abstract:

    Methoxymethane (called dimethyl ether, DME) is recognized as a promising alternative refrigerant. Knowledge of the phase equilibrium behavior of DME-lubricant is essential for selecting a suitable oil. A long-term systematic research program on the phase equilibrium for systems of DME and oils was carried out in our laboratory, making the effort to determine its dependence on the molecular structure of oils, temperature, and pressure. In this article, phase equilibrium data of the DME + Pentaerythritol tetraheptanoate system and the DME + Pentaerythritol tetranonanoate system were reported from (293.15 to 353.15) K using the isochoric saturation method. Experimental data of phase equilibrium were modeled by the Peng–Robinson (PR) equation of state using the HVOS mixing rule and the NRTL excess-free-energy model. Moreover, the influence of the molecular weight of Pentaerythritol esters on the phase equilibrium behavior of DME/ester mixtures was analyzed.

  • Solubility of dimethyl ether in Pentaerythritol tetrabutyrate and in Pentaerythritol tetrapentanoate. Comparison with other Pentaerythritol tetraalkyl esters
    The Journal of Chemical Thermodynamics, 2015
    Co-Authors: Yanjun Sun, Xiaopo Wang, Na Gong, Zhigang Liu
    Abstract:

    Abstract The solubilities of dimethyl ether (DME) in Pentaerythritol tetrabutyrate (PEC4) and in Pentaerythritol tetrapentanoate (PEC5) between T  = (283.15 and 353.15) K have been measured by isochoric saturation method. The experimental solubility data were correlated by the Peng–Robinson equation of state with HVOS mixing rule in which the excess Gibbs free energy at infinite pressure was represented by the NRTL equation. In addition, an analysis of the influence of the molar mass on the solubility of DME in PECs over a wide range of temperature and pressure was performed.

Nur Atiqah Mohamad Aziz - One of the best experts on this subject based on the ideXlab platform.

  • application of response surface methodology rsm for optimizing the palm based Pentaerythritol ester synthesis
    Industrial Crops and Products, 2014
    Co-Authors: Nur Atiqah Mohamad Aziz, Robiah Yunus, Umer Rashid, Azhari Muhammad Syam
    Abstract:

    Abstract The present study was performed to optimize reaction parameters for the transesterification reaction of palm oil methyl ester and Pentaerythritol by using response surface methodology (RSM). The affecting parameters were selected as temperature (140–190 °C), amount of catalyst (0.5–1.5 wt%), palm oil methyl ester-to-Pentaerythritol molar ratio (4:1–5:1) and reaction time (1–5 h), in order to produce Pentaerythritol ester (tetraester). The optimum operating conditions; temperature at 158 °C; amount of catalyst, 1.19 wt%; molar ratio, 4.5 and 1 h of reaction time were obtained with the result of the Pentaerythritol ester's yield of 40.13%. The interaction parameter of the catalyst amount with the palm oil methyl ester-to-Pentaerythritol molar ratio was found to be the most significant amongst all of the interaction parameters. The Pentaerythritol ester properties were analyzed and compared with the commercial oven chain lubricant. The results indicated that the Pentaerythritol ester is able to withstand a high temperature environment with a flash point of 302 °C and viscosity of 12.7 cSt at 100 °C.

Thomas M Klapotke - One of the best experts on this subject based on the ideXlab platform.

  • Pentaerythritol based energetic materials related to petn
    European Journal of Organic Chemistry, 2015
    Co-Authors: Quirin J. Axthammer, Burkhard Krumm, Thomas M Klapotke
    Abstract:

    New tetravalent Pentaerythritol tetranitrocarbamate (PETNC) and its tetraammonium salt have been synthesized by an efficient two-step synthesis starting from the cheap and commercially available Pentaerythritol. In addition to full spectroscopic characterization, their thermal stabilities were examined by differential thermal analysis, and their energies of formation calculated. Furthermore, the structures were determined by X-ray diffraction.

  • Pentaerythritol‐Based Energetic Materials Related to PETN
    European Journal of Organic Chemistry, 2014
    Co-Authors: Quirin J. Axthammer, Burkhard Krumm, Thomas M Klapotke
    Abstract:

    New tetravalent Pentaerythritol tetranitrocarbamate (PETNC) and its tetraammonium salt have been synthesized by an efficient two-step synthesis starting from the cheap and commercially available Pentaerythritol. In addition to full spectroscopic characterization, their thermal stabilities were examined by differential thermal analysis, and their energies of formation calculated. Furthermore, the structures were determined by X-ray diffraction.

  • the sila explosives si ch2n3 4 and si ch2ono2 4 silicon analogues of the common explosives pentaerythrityl tetraazide c ch2n3 4 and Pentaerythritol tetranitrate c ch2ono2 4
    Journal of the American Chemical Society, 2007
    Co-Authors: Thomas M Klapotke, Burkhard Krumm, Rainer Ilg, Dennis Troegel, Reinhold Tacke
    Abstract:

    The reaction of tetrakis(chloromethyl)silane, Si(CH2Cl)4, with sodium azide afforded tetrakis(azidomethyl)silane (sila-pentaerythrityl tetraazide, Si(CH2N3)4 (1b)). Nitration of tetrakis(hydroxymethyl)silane, Si(CH2OH)4, with nitric acid resulted in the formation of tetrakis(nitratomethyl)silane (sila-Pentaerythritol tetranitrate, Si(CH2ONO2)4 (2b)). Compounds 1b and 2b are extremely shock-sensitive materials and very difficult to handle. Spectroscopic data were obtained as good as sensitivity and safety allowed for umambiguous identification. Quantum chemical calculations (DFT) of the C/Si pairs C(CH2OH)4/Si(CH2OH)4, 1a/1b, and 2a/2b regarding the structures and electronic populations were performed.

Mauro Scattolini - One of the best experts on this subject based on the ideXlab platform.

  • Solubility measurements and correlation of carbon dioxide in Pentaerythritol tetra-2-methylhexanoate. Comparison with other Pentaerythritol esters
    Fluid Phase Equilibria, 2009
    Co-Authors: Sergio Bobbo, Laura Fedele, Mauro Scattolini, Francesco Pernechele, Roman Stryjek
    Abstract:

    Abstract The solubility of carbon dioxide in Pentaerythritol tetra-2-methylhexanoate between 243.15 K and 343.15 K and between 0.1 MPa and 10 MPa is presented, together with a comparison with the already studied systems of carbon dioxide and Pentaerythritol esters, i.e. pure precursors of commercial lubricants. The experimental data were regressed on the basis of the Peng–Robinson equation of state with the Huron–Vidal mixing rules with the excess Gibbs energy at infinite pressures.

  • PρT Experimental Measurements and Data Correlation of Pentaerythritol Esters
    Journal of Chemical & Engineering Data, 2007
    Co-Authors: Laura Fedele, Sergio Marinetti, And Sergio Bobbo, Mauro Scattolini
    Abstract:

    The new refrigerant fluids are generally not compatible with traditional mineral oils used for the lubrification of compressors. Different typologies of oils have been proposed, such as polyalkylene glycol (PAG), alkylbenzene (AB), and polyol ester (POE) oils. New thermodynamic models are necessary to describe well the behavior of these fluids, but at the moment only few experimental data are available in the literature. The work presented in this paper is part of our research program aimed to evaluate the solubility of refrigerants in commercial oils. The density of five different Pentaerythritol esters is presented, which are used as components of the commercial POE oils (i.e., Pentaerythritol ester of butyric acid (PEC4), Pentaerythritol ester of valeric acid (PEC5), Pentaerythritol ester of hexanoic acid (PEC6), Pentaerythritol ester of heptanoic acid (PEC7), and Pentaerythritol ester of octanoic acid (PEC8)). The experimental compressed liquid density data were correlated by means of a particular equ...