DOCSLIB.ORG

Physical Properties of Triglycerides IV. Dielectric Constant by Dr

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Physical Properties of Triglycerides IV. Dielectric Constant by Dr Physical Properties of Triglycerides IV. Dielectric Constant By Dr. Ir. T. H. GOUW"and Prof. Dr. Ir. J. C. Vlugter"" L)e~iur&meri~of Chentical Engineering, Technological University, DelfL. The Netherlands Dielectric constants at 200 and at 40OC of a number of trigly- Propridtds physiques des triglycdrides IV: Constante didlectrique cerides in the liquid state have been measured. A molar additive La constante dielectrique a 20 ou 40°C a ete trouvee suru function of the dielectric constant, based on a relation derived un nombre de triglycerides a I'etat liquide. A l'aide d'une by J. van Elk, was used in combination with a previously derived equation precedemment derives pour les triglycerides, conjointe- equation for triglycerides to give an equation whicfi relates the ment avec une fonction additive molaire de la constante dielec- dielectric constant of a triglyceride or triglyceride mixture to trique, qui est basee sur une relation obtenue par J. van Elk, its refractive index, density, and iodine value. Quantification of on a etabli une equation qui fournit les relations entre la con- this relation was based on prime data obtained from these model stante dielectrique d'un triglyceride ou d'un melange de trigly- triglycerides and from previously published data on fatty acid cerides et leur indice de refraction, densite et indice d'iode. methyl esters. +MwqeciiMe cBoi4crr3a TpMrJMqepiiAoB. CooBqeiiue 4: Ati- xiewpMaeclcaa nucwmwax. Physikalishe Eigenschaften von Triglyceriden IV: DielektrizitPts- konstante &TSI PSIAa TPMr~7MqepM~OBU XMAKOM COCTOSIHMH OIlpe- jenerw AM~.~~KTPMWCKM~IIocTonHHbxe npx 20 M 40° C. Bei einer in flussigem Anzahl von Triglyceriden Zustand wurde c IIOMOqbIO PaHee Bbll3eAeHHOI'O YpaBHeHMJi AJSI TpMPJIM- die Dielektrizitatskonstante bei 200 bzw. 400 C ermittelt. Unter lJ,epMAOB M MOJISIPHOU aAAUTMBHOfi (PYHICqHIi JM3.TeWrpH- Zuhilfenahme einer fruher ahgeleiteten Gleichung fur die Tri- ~IeCKOnnOCTOSIHHO8, Ga3~py101qeflc~Ha IIOJI>'qeHHOM RaH. glyceride zusammen mit einer molaren additiven Funktion der D.1bKOM COOTHOLUeHMM, IIOlIyYeHO ypaBHel1Me J.1.R COOTHO- Dielektrizitatskonstante, die auf einer von J. van Elk erhaltenen LLIeHMR MeXAy j&MMIeICTpMqeCKOfi IIOCTORHHOfi TpMFJIHqe- Beziehung beruht, wurde eine Gleidmng aufgestellt, die die Be- p~firtM cMecM TpwmiqepMAoB M MX Kox])(PMqMewrw npe- ziehungen zwiscfien der Dielektrizitatskonstante eines Triglycerids .10MJleHUR, nJIOTHOCTbI0 M fiOJHblM YMCJIOM. nPMBOASITCR oder Triglycerid-Gemiscfies und deren Brecfiungsindex, Dihte und lcOJIMYeCTBeHIlbIe AaHHhIe 8TOrO COOTHOLUCHMSI Ila OCHOBB- Jodzahl ergibt. Quantitative Aussagen dieser Beziehung wurden HUN AaHHbIX J.rlSI hIOxe.lbHbIX TpMrJlMqepMAOB M pallee auf Grundlage der Daten bei Modell-Triglyceriden und aus bereits OIIy6JIMKORallHbIX AaHHbIX A.7R Mf?TN.'IOBbIX 3CbUpOII 5KNP- veroffentlihten Werten fur Fettsaure-methylester gemacfit. HIJX KMC;IOT. Introduction In this relation z stands for the increment of the The dielectric constant of a material, E, is defined atom i, and c is the number of the atoms i in the mole- as the ratio of the capacitance of a condenser with the cule. M stands for the molecular weight and d is the investigated substance between the plates, C, and the density. capacitance when a vacuum separates the plates, C,. Additive behaviour was ascribed to this function and C. B. Hence, Thwing obtained excellent results for many compounds. Other investigators have, however, noted significant differences be- E = c/c, (1) tween predicted ahd observed values. P. Waldene mentions and the dielectric constant thus defined is dimensionless. tetranitromethane for which 104.3 is predicted whereas a This value, also called the static or the quasi-static value of only 2.1 is observed. To obtain improved predictions P. Walden assumed atomic groups to contribute to the dielectric constant, is measured in a static field or in dielectric behaviour. A distinction is made between dielec- an alternating electric field of low frequency. trophoric and dielectrogenic groups. The high contribution of The first systematic measurements on the dielectric constant a dielectrophoric group is only noticeable in the presence of of fatty acids and triglycerides were carried out more than a dielectrogenic group in the same chain. half a century ago; L. Kahlenberg 1 observed that the dielectric H. Kauffmann7 made a further study on the influence of constant of natural fatty oils with a high percentage of oleic these groups in different positions in the molecule. He ob- acid was quite similar to the dielectric constant of the acid served the general trend in homologous series, the influence itself. In the following years only a small number of studies of branching, unsaturation, and substitution on the value of on this subject was noted. A review by W. S. Singleton4 the dielectric constant. adequately covers this subject up to 1958. Of the more The chief deficiency in all these methods is the in- recent papers mention can be made of the investigations of ability to account for changes in configuration or for K. H. Ludde' on the dielectric and refractometric behaviour geometrical isomers, and it is in exactly these areas of fats on aging. Of interest is also the correlation between where dipole moment measurements have been very the dielectric constant and the iodine value, which R. R. Allen successful in resolving structural problems. The correct observed over the commercially important range of fatty oils. s additive formula should, therefore, contain vectorial Additive Functions of the Dielectric Constant terms to account for those molecular structures, whose contribution to E depends on its direction in space. One first attempts to predict the dielectric con- of the Existing additive functions are, however, still quite stant, E, from structural contributions was presented by adequate if one would only restrict the applicability C. B. Thwing5, who proposed the following relation: to a limited area. In our particular case, where we have limited ourselves to triglycerides with non-polymerized, non-conjugated, straight-chain component fatty acids, Present addresses: we have noted that good results are obtained by the '* Chevron Research Co., Richmond. Calif., U. S. A. 94 802. use of a semi-empirical additive function for homo- * Technische Hogeschool Twente, Enschede, The Netherlands. logous series recently derived by J. van Elk8. This func- 1 Trans. Amer. Electrochem. SOC.7, 167 [1905]. tion reads: 2 W.S. Singleton, in: Fatty Acids, Part. I, Editor K. S. Mark- ley, Interscience, New York 1960. 6 Z. physik. Chem. 70, 584 [1910]. Fette . Seifen . Anstrihmittel 61, 1156 [1959]. ' Beziehungen zwischen physikalischen Eigenschaf ten und che- J. Amer. &em. SOC.52, 671 [1955]. mischer Konstitution, Ferdinand Enke, Stuttgart 1920. 5 Z. physik. Chem. 14, 286 [1894]. * Thesis, Delft 1962. FETTE . SEIFEN . ANSTRICHMITTEL 69. Jahrgang Nr. 4 1967 223 Em = (~-1)"~M/d = Xqzi (3) Temperature In analogy to other molar quantities described in this Readings were taken with calibrated thermometers, series of communications we will term E,, the molar the control being better than 0.02O C at 20° C and 0.loC dielectric constant. It has the same dimensions as the at 40° C. molar volume and the molar refraction, i. e., ml/gmole. In our particular case E,, is not obtained by summation Products of atomic, but of group contributions. To ensure iin- The investigated products included all mono-acid proved accuracies we will consider the largest groups triglycerides with even-numbered component fatty acids possible in our area of study without the sacrifice of up to trilaurin, a number of mono-acid unsaturated versatility. triglycerides, and some mixed triglycerides. Their pre- paration and physical properties have already been Experimental described in previous communications I5-l7. Apparatus Measurements have been carried out on a commercial Results Multi-DK-meter (type DK 06-22 manufactured by Dr. With a single exception we could not ascertain any Slevogt, Weilheim). A description of the apparatus and comparable data in the literature. The observed dielec- the measuring procedure have already been published tric constants at 2OoC have been included in Table 1 in the literature O, lo. and those at 4OoC in Table 2. Em is the molar dielectric constant. The molar volume, M/d, has been obtained from a previous paper Is. XE is the sum of the molar Calibration ",' dielectric constants of the component fatty acid methyl The purification of calibration liquids for dielectric esters. Values of Em for the fatty acid methyl esters measurements has already been discussed in details by have already been published previously lo. The difference E. Oelimeo~lland by R. R. Mecke and coworkersIe. Al- most all standards used in these investigations have between En, of the triglyceride and the XE ",' of its been purified along the discussed lines. The compounds component fatty acids in the methyl ester form is called chosen as standards, viz., benzene, cyclohexane, di-n- r, the glyceride incrementt5. EF is the increment of the butyl ether, carbon tetrachloride, 1,i?-dichloroethane, and double bond. It has been obtained as one third the chlorobenzene, were already available in relatively high difference between the relative compounds. The E,,, of purity. Depending on the compound the final purifica- tristearin, included to facilitate comparison, has been tion of these products consisted of either a chemical computed by subtracting the average r from three times clean-up
Load more

Recommended publications
  • Esterifikasi Gliserol Dari Produk Samping Biodiesel Menjadi Triasetin Menggunakan Katalis Zeolit Alam
    Esterifikasi Gliserol Dari Produk Samping Biodiesel Menjadi Triasetin Menggunakan Katalis Zeolit Alam Nirmala Sari 1, Zuchra Helwani 2, dan Hari Rionaldo3 Laboratorium Teknologi Oleokimia Program Studi Teknik Kimia S1, Fakultas Teknik Universitas Riau Kampus Binawidya Km. 12,5 Simpang Baru Panam, Pekanbaru 28293 *Email : [email protected] ABSTRACT Glycerol is a by-product of biodiesel production from transesterification reaction generated 10% volume product. The increase of biodiesel production is followed by the increase of the glycerol as by product. Glycerol when esterified with acetic acid formed Triacetin. Triacetin has many uses for food, non-food and additives in biofuel feedstock that is renewable and environmentally friendly. In this study will be make Triacetin from reaction esterification of crude glycerol purified with acetic acid glacial and using natural zeolite catalyst has been activated. Making triacetin performed with a three-neck flask equipped with a condenser, heating mantle, thermometer and magnetic stirred at 100 ° C, 100 mesh size catalyst and reaction time for 4 hours. Process of qualitative analysis using FT-IR instrument has detected the exixtence of Triacetin product. The variables are varied ratio reactant of glycerol and acetic acid, and the concentration catalyst. The highest conversion obtained for 90.02% in reactan ratio mol glycerol and acetic acid 1: 7, catalyst concentration of 3% to weight of acetic acid. Comparison of reagents give real effect to the conversion of glycerol into Triacetin, while the catalyst concentration does not give a significant effect on glycerol conversion be Triacetin. Keywords: acetic acid, esterification, glycerol, Triacetin 1. Pendahuluan Gliserol merupakan produk samping gliserol ester maleat resin.
    [Show full text]
  • Questions: Physical Properties and 7 Step Process
    Questions: Physical Properties and 7 Step Process 1. Why does a water-saturated sandstone typically have a higher P-wave velocity than a dry sandstone? A saturated sandstone: a. is more dense b. has a larger bulk modulus c. has a larger shear modulus d. has a higher tensile strength 2. The relative permittivity of a given rock is considered large when: a. it contains a lot of pore water b. an applied electric field results in a larger electric dipole moment c. it has a value of 30 d. b and c are correct e. a,b and c are correct 3. You measure a resistance of 16 kΩ between two parallel faces of a 2cm x 2cm x 2cm cube. Determine the resistivity. a. 320 Ωm b. 800000 Ωm c. 32000 Ωm d. 8000 Ωm 4. You are flying a gravity survey over a sedimentary basin. The flight path crosses a known dyke. What would be the expected gravity response and why? a. Gravity high over the dyke; the dyke is more dense than the background b. Gravity low over the dyke; the dyke is less dense than the background c. Gravity high over the dyke; the dyke is less dense than the background d. Gravity low over the dyke; the dyke is more dense than the background 5. You are building a road through known active Karst terrain in Ireland. Which set of physical property contrasts would be most diagnostic for locating regions where sink- holes could form? a. Karstified: low density, Limestone: high density b. Karstified: low resistivity, Limestone: high resistivity c.
    [Show full text]
  • Triglyceride Transesterification in Heterogeneous Reaction System with Calcium Oxide As Catalyst
    Rev. Fac. Ing. Univ. Antioquia N.° 57 pp. 7-13. Enero, 2011 Triglyceride transesterification in heterogeneous reaction system with calcium oxide as catalyst Transesterificación de triglicéridos en el sistema de reacción heterogénea con óxido de calcio como catalizador Mónica Becerra Ortega, Aristóbulo Centeno Hurtado, Sonia Azucena Giraldo Duarte* Centro de Investigaciones en Catálisis (CICAT). Escuela de Ingeniería Química. Universidad Industrial de Santander (UIS). Carrera 27 Calle 9. Bucaramanga. Colombia (Recibido el 03 de febrero de 2010. Aceptado el 15 de octubre de 2010) Abstract In this work, the behavior of the CaO as a potential catalyst for the transesterification of triglyceride towards biodiesel production was studied. The effect of the alcohol type, the ratio of alcohol/triacetin, the amount of catalyst, and the chain length of triglyceride on the catalytic behavior of CaO was analyzed. Total conversion was obtained at room temperature with a 6:1 molar ratio of methanol to triacetin over 1% of CaO, after 1 h. It was demonstrated that the whole reaction occurs in heterogeneous phase. During five reaction cycles the CaO maintained a high catalytic activity, showing its good stability. Additionally, it was established that the length of the triglyceride used influenced the transesterification reaction yield due to the steric hindrances and diffusional limitations in the fluid phase. ----- Keywords: Biodiesel, triacetin, basic catalysis, triolein Resumen En este trabajo se estudió el comportamiento del CaO como potencial catalizador en la transesterificación de trigliceridos para la producción de biodiesel. Se analizó el efecto del tipo de alcohol, la relación molar alcohol/triacetina, la cantidad de catalizador y el tamaño de la cadena del triglicérido sobre su comportamiento catalítico.
    [Show full text]
  • AC Measurement System (ACMS) Option User's Manual
    Physical Property Measurement System AC Measurement System (ACMS) Option User’s Manual Part Number 1084-100 C-1 Quantum Design 11578 Sorrento Valley Rd. San Diego, CA 92121-1311 USA Technical support (858) 481-4400 (800) 289-6996 Fax (858) 481-7410 Fourth edition of manual completed June 2003. Trademarks All product and company names appearing in this manual are trademarks or registered trademarks of their respective holders. U.S. Patents 4,791,788 Method for Obtaining Improved Temperature Regulation When Using Liquid Helium Cooling 4,848,093 Apparatus and Method for Regulating Temperature in a Cryogenic Test Chamber 5,311,125 Magnetic Property Characterization System Employing a Single Sensing Coil Arrangement to Measure AC Susceptibility and DC Moment of a Sample (patent licensed from Lakeshore) 5,647,228 Apparatus and Method for Regulating Temperature in Cryogenic Test Chamber 5,798,641 Torque Magnetometer Utilizing Integrated Piezoresistive Levers Foreign Patents U.K. 9713380.5 Apparatus and Method for Regulating Temperature in Cryogenic Test Chamber CONTENTS Table of Contents PREFACE Contents and Conventions ...............................................................................................................................vii P.1 Introduction .......................................................................................................................................................vii P.2 Scope of the Manual..........................................................................................................................................vii
    [Show full text]
  • Lab 1 - Physical Properties of Minerals
    Page - Lab 1 - Physical Properties of Minerals All rocks are composed of one or more minerals. In order to be able to identify rocks you have to be able to recognize those key minerals that make of the bulk of rocks. By definition, any substance is classified as a mineral if it meets all 5 of the following criteria: - is naturally occurring (ie. not man-made); - solid (not liquid or gaseous); - inorganic (not living and never was alive); - crystalline (has an orderly, repetitive atomic structure); - a definite chemical composition (you can write a discrete chemical formula for any mineral). Identifying an unknown mineral is like identifying any group of unknowns (leaves, flowers, bugs... etc.) You begin with a box, or a pile, of unknown minerals and try to find any group features in the samples that will allow you to separate them into smaller and smaller piles, until you are down to a single mineral and a unique name. For minerals, these group features are called physical properties. Physical properties are any features that you can use your 5 senses (see, hear, feel, taste or smell) to aid in identifying an unknown mineral. Mineral physical properties are generally organized in a mineral key and the proper use of this key will allow you to name your unknown mineral sample. The major physical properties will be discussed briefly below in the order in which they are used to identify an unknown mineral sample. Luster Luster is the way that a mineral reflects light. There are two major types of luster; metallic and non-metallic luster.
    [Show full text]
  • Properties of Matter
    Properties of Matter Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable version of this book, as well as other interactive content, visit www.ck12.org CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the FlexBook®, CK-12 intends to pioneer the generation and distribution of high-quality educational content that will serve both as core text as well as provide an adaptive environment for learning, powered through the FlexBook Platform®. Copyright © 2013 CK-12 Foundation, www.ck12.org The names “CK-12” and “CK12” and associated logos and the terms “FlexBook®” and “FlexBook Platform®” (collectively “CK-12 Marks”) are trademarks and service marks of CK-12 Foundation and are protected by federal, state, and international laws. Any form of reproduction of this book in any format or medium, in whole or in sections must include the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in addition to the following terms. Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution/Non- Commercial/Share Alike 3.0 Unported (CC BY-NC-SA) License (http://creativecommons.org/licenses/by-nc-sa/3.0/), as amended and updated by Creative Commons from time to time (the “CC License”), which is incorporated herein by this reference.
    [Show full text]
  • 2013 Annual Meeting Abstracts Biotechnology
    2013 Annual Meeting Abstracts Biotechnology MONDAY AFTERNOON BIO 1.1/PHO 1: Polar Lipids: Chemistry, Technology, and Applications Chair(s): X. Xu, Wilmar Global R&D Center, China; Aarhus University, Denmark; M. Ahmad, Jina Pharmaceuticals Inc., USA Enzymatic "green" Preparation of Sugar-fatty Acid Esters D. Hayes(1) (1)University of Tennessee, United States of America Saccharide-fatty acid esters are an emerging category of biobased surfactants prepared entirely from renewable resources that are used as emulsifiers in foods, cosmetics, and pharmaceuticals, and possess anticancer and insecticidal properties. Typically, the esters are prepared chemically under harsh condition: temperatures near 200 C, employment of solvents, etc., which can cause undesirable side-reactions and produce waste products. Our group has been investigating the use of lipases and novel bioreactor system design to prepare sugar esters under solvent-free conditions and relatively low temperature: ~65 C. Using a stoichiometric feed of saccharide and fatty acid, our approach achieves 90-95% pure ester on a 10-30 gram scale, which, due to the absence of excess reactants and solvent, will require little or no further downstream purification to achieve industrial specifications. The presentation will provide an overview of our recent work, including an evaluation of its physical properties. Deep Eutectic Solvents: new Opportunities for Lipase-catalyzed Reactions E. DURAND(1), J. LECOMTE(2), B. BAREA(3), P. VILLENEUVE(4) (1)CIRAD, UMR IATE, France (2)CIRAD, UMR IATE, France (3)CIRAD, UMR IATE, France (4)CIRAD, UMR IATE, France In recent years, researchers focused on finding green alternative media to organic solvents for enzyme-catalyzed reactions.
    [Show full text]
  • Dielectric Properties and Other Physical Properties of Low-Acyl Gellan Gel As Relevant to Microwave Assisted Pasteurization Proc
    Journal of Food Engineering 149 (2015) 195–203 Contents lists available at ScienceDirect Journal of Food Engineering journal homepage: www.elsevier.com/locate/jfoodeng Dielectric properties and other physical properties of low-acyl gellan gel as relevant to microwave assisted pasteurization process ⇑ Wenjia Zhang a, Donglei Luan a, Juming Tang a, , Shyam S. Sablani a, Barbara Rasco b, Huimin Lin a, Fang Liu a a Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States b UI/WSU bi-State School of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164-6120, United States article info abstract Article history: Various model foods were needed as chemical marker carriers for the heating pattern determination in Received 1 April 2014 developing microwave heating processes. It is essential that these model foods have matching physical Received in revised form 5 October 2014 properties with the food products that will be microwave processed, such as meat, vegetables, pasta, Accepted 13 October 2014 etc. In this study, the physical properties of low acyl gellan gel were investigated to evaluate its suitability Available online 22 October 2014 to be used as a possible model food for the development of single mode 915 MHz microwave assisted pasteurization processes. These physical properties included the dielectric properties, gel strength and Keywords: water holding capacities. In order to adjust the dielectric constant and loss factor, various amounts of Low acyl gellan gel sucrose (0, 0.1, 0.3 and 0.5 g/mL (solution)) and salt (0, 100, 200, and 300 mM) were added to 1% gellan Dielectric properties 2+ Gel strength gel (with 6 mM Ca addition).
    [Show full text]
  • PROPERTIES of MATERIALS This Page Intentionally Left Blank Properties of Materials Anisotropy, Symmetry, Structure
    PROPERTIES OF MATERIALS This page intentionally left blank Properties of Materials Anisotropy, Symmetry, Structure ROBERT E. NEWNHAM Pennsylvania State University 1 3 Great Clarendon Street, Oxford OX26DP Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Bangkok Buenos Aires Cape Town Chennai Dar es Salaam Delhi Hong Kong Istanbul Karachi Kolkata Kuala Lumpur Madrid Melbourne Mexico City Mumbai Nairobi São Paulo Shanghai Taipei Tokyo Toronto Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York © Oxford University Press 2005 The moral rights of the authors have been asserted Database right Oxford University Press (maker) First published 2005 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose this same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Data available ISBN 0-19-852075-1 (hbk) ISBN 0-19-852076-x (pbk) 10987654321 Typeset by Newgen Imaging Systems (P) Ltd., Chennai, India Printed in Great Britain on acid-free paper by Antony Rowe, Chippenham Preface This book is about anisotropy and structure–property relationships.
    [Show full text]
  • Conducting Properties of Polypropylene/ Carbon Nanofiber Composites
    16TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS CONDUCTING PROPERTIES OF POLYPROPYLENE/ CARBON NANOFIBER COMPOSITES W. H. Zhong, G. Sui, M. A. Fuqua and C. A. Ulven Department of Mechanical Engineering North Dakota State University, Fargo, ND 58105, USA Keywords: carbon nanofibers, polypropylene, nanocomposites, conductivity Abstract particular, very few have reported work Effects of carbon nanofibers (CNFs) on addressing the effects of CNFs on the final the microstructure and properties of semi- properties of the resulting nanocomposites crystalline polymers were studied based on through the crystallization behavior of the preparation of polypropylene (PP) polymer matrix. nanocomposites by a twin-screw extrusion. As an effective processing method, twin- Crystallization behavior and morphology, as screw extrusion can play an important role in well as dielectric property, thermal and preparing of nanocomposites to obtain electrical conductivity of the CNF/PP nanocomposites with uniform microstructure nanocomposites were characterized. The [4-6]. degree of crystallinity of the PP exhibited an This paper introduces the preparation increased trend with addition of CNFs carbon nanofiber/PP nanocomposites by a followed by moderate decreases at higher Micro-18mm twin-screw extruder which can content. The PP nanocomposite containing provide the high shear compounding for 5wt% CNFs exhibited a surprisingly high polymer melts. After a great deal of dielectric constant under wide sweep exploring experiments, the optimal extruding frequencies attended by low dielectric loss. procedures for carbon nanofiber/PP With the increasing of CNF content, nanocomposites were established. The aim of electrical and thermal conductivities of the present work is to study the effects of nanocomposites were enhanced continuously. carbon nanofiber content on crystallization behavior, mechanical properties, thermal 1.
    [Show full text]
  • Chemical Kinetics for Synthesis of Triacetin from Biodiesel Byproduct
    www.ccsenet.org/ijc International Journal of Chemistry Vol. 4, No. 2; April 2012 Chemical Kinetics for Synthesis of Triacetin from Biodiesel Byproduct Zahrul Mufrodi Department of Chemical Engineering, Ahmad Dahlan University 9 Kapas Street, Yogyakarta 55166, Indonesia Tel: 62-274-743-6596 E-mail: [email protected] Sutijan, Rochmadi & Arief Budiman Department of Chemical Engineering, Gadjah Mada University 2 Grafika Street, Yogyakarta 55281, Indonesia Received: December 9, 2011 Accepted: January 29, 2012 Published: April 1, 2012 doi:10.5539/ijc.v4n2p101 URL: http://dx.doi.org/10.5539/ijc.v4n2p101 The research is financed by KKP3T department of agriculture and Department of national education Indonesia Abstract The reaction kinetic of the glycerol acetylation with acetic acid catalyzed by sulfuric acid has been studied in the frame of continuous triacetin production. Glycerol, acetic acid and sulfuric acid catalyst were reacted in a batch reactor, in order to get reaction kinetics data. The mole ratio of catalyst to glycerol and temperature were studied during the experience. This study concluded that the selectivity of triacetin increased with increase in mole ratio of catalyst to glycerol. Increasing temperatures lead to increase selectivity of triacetin. It will decreased at the time of acetic acid has begun to evaporate. Triacetin synthesis is an exothermic reaction, a higher reaction temperature will cause in shifting the balance toward formation of reactants. This needs to be anticipated by taking one of the products so that the equilibrium shifting toward product formation. Keywords: Reaction kinetic, Glycerol, Acetylation, Triacetin, Acetic acid 1. Introduction Needs of oil energy sources from fossil fuels are increasing, while inventories are running low.
    [Show full text]
  • PARTIAL CHARACTERIZATION of LIPASE from COCOA BEANS (Theobroma Cacao
    448 Indo. J. Chem., 2008, 8 (3), 448 - 453 PARTIAL CHARACTERIZATION OF LIPASE FROM COCOA BEANS (Theobroma cacao. L.) OF CLONE PBC 159 Ratna Agung Samsumaharto Faculty of Biology, Setia Budi University, Jl. Let. Jend. Sutoyo Mojosongo – Surakarta 57127 Received 3 April 2008; Accepted 15 October 2008 ABSTRACT A study was carried out to characterize the cocoa lipase from cocoa beans (Theobroma cacao, L.) of clone PBC 159. The optimum temperature of cocoa lipase was 30-40 °C and the pH optimum was 7.0-8.0. The moleculer weight of the lipase enzyme was in between 45-66 kDa. The results indicate that Km value for cocoa bean lipase was 2.63 mM, when trimyristin was used as a substrate. The incubation of cocoa bean lipase with triolein and tributyrin (as substrate) yielded Km of 11.24 and 35.71 mM, respectively. The Vmax value obtained from the incubation of the lipase with a wide range of substrates, including tributyrin, trimyristin and triolein, are expressed as µmole acid/min/mg protein for cocoa lipase. Vmax values decreased with the increase in the triacylglycerol chain-length, with Vmax values of 27.78, 13.16 and 11.63 µmole acid/min/mg protein when incubated with tributyrin, trimyristin and triolein, respectively. Inhibition of lipase occurred in the presence of diisopropyl flourophosphate, N- bromosuccinimide and 5,5-dithiobis-(-2-nitrobenzoic acid). Keywords: characterization, lipase, cocoa beans INTRODUCTION According to Hassan [8] the lipase showed that the optimum temperature for oil palm mesocarp lipase Lipases are ester hydrolases or esterases since activity range between 20.0 to 32.5 °C.
    [Show full text]