DOCSLIB.ORG

Thermal Analysis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Analysis TECHNIQUE NOTE Thermal Analysis The scientists at EAG are experts in using thermal analysis techniques for materials characterization as well as for designing custom studies. This application note details TGA (Thermogravimetric Analysis), TG-EGA (Thermogravimetric Analysis with Evolved Gas Analysis), DSC (Differential Scanning Calorimetry), TMA (Thermomechanical Analysis) and DMA (Dynamic Mechanical Analysis). These techniques have played key roles in detailed materials identifications, failure analysis and deformulation (reverse engineering) investigations. THERMOGRAVIMETRIC ANALYSIS (TGA) DESCRIPTION • Vaporization, sublimation TGA measures changes in sample weight in a controlled thermal • Deformulation/failure analysis environment as a function of temperature or time. The changes in • Loss on drying sample weight (mass) can be a result of alterations in chemical or • Residue/filler content physical properties. • Decomposition kinetics TGA is useful for investigating the thermal stability of solids and liquids. A sensitive microbalance measures the change in mass of STRENGTHS the sample as it is heated or held isothermally in a furnace. The • Small sample size purge gas surrounding the sample can be either chemically inert • Analysis of solids and liquids with minimal sample preparation or reactive. TGA instruments can be programmed to switch gases during the test to provide a wide range of information in a single • Quantitative analysis of multiple mass loss thermal events experiment. from physical and chemical changes of materials • Separation and analysis of multiple overlapping mass loss COMMON APPLICATIONS events • Thermal stability/degradation studies LIMITATION • Investigating mass losses resulting from physical and chemical changes • Evolved products are identified only when the TGA is connected to an evolved gas analyzer (e.g. TGA/MS or TGA/ • Quantitation of volatiles/moisture FTIR) • Screening additives COPYRIGHT © 2017 EAG, INC. | REV. 11.16.18 M-003416 EAG.COM Thermal Analysis THERMOGRAVIMETRIC ANALYSIS WITH EVOLVED GAS ANALYSIS (TG-EGA)590 °C 580 °C 10 0 -10 -20 CO2 TG, % -30 Abs, au Abs, -40 0 200 400 600 800 Abs, au Abs, Temp, °C CO C H OH 6 5 600 ºC H2O Abs, au Abs, 580 ºC Abs, au Abs, 560 ºC Abs, au Abs, 4000 3500 3000 2500 2000 1500 1000 500 Wave Number, cm-1 4000 3500 3000 2500 2000 1500 5001000 ºC 500 Wave Number, cm-1 4000 3500 3000 2500 2000 1500 4001000 ºC 500 Wave Number, cm-1 4000 3500 3000 2500 2000 1500 1000 500 Wave Number, cm-1 4000 3500 3000 2500 2000 1500 1000 50000 Wave Number, cm-1 DESCRIPTION COMMON APPLICATIONS TG-EGA instrumentation is used to study the physical and • Thermal stability (degradation) studies chemical processes that result in mass loss or gain. Like standard • Monitoring mass changes under controlled gas atmosphere TGA, the sample is heated in a controlled gas atmosphere using and temperature with identification of off-gassing and a programmed temperature sweep or isothermal hold. But TG- pyrolysis products EGA goes one step further: a gas analyzer is coupled to the TGA • Analyzing trace volatiles, dehydration, additives, chemical furnace using a heated transfer line, which enables analysis of the reactions, formulation components, mechanism of gases evolved by the sample during heating and pyrolysis. The decomposition evolved gas analyzer is used to identify the chemistries present in the off-gassing and pyrolyzed components. • Analysis of polymers, organic and inorganic materials Evolved Gas Analyzer options for TG-EGA include: STRENGTHS • Fourier Transform Infrared Spectrophotometer (FTIR) – • Simultaneous thermogravimetric analysis (TGA) and identification of chemical family, and, in some cases, specific characterization of evolved chemical residuals compound • Small sample size • Mass Analyzer – chemical residuals are specifically assigned, • Analysis of solids and liquids with minimal sample preparation but sometimes have other possible answers • Detection of multiple mass loss thermal events from physical and chemical changes of materials LIMITATIONS TGA/DTA • TGA-FTIR does not detect non-polar molecules, such as H2, N2, O2 ∆T kg • TGA-FTIR spectral identification of product gases may be limited to chemical family or class • Secondary gas-phase reactions can complicate identification of product gases COPYRIGHT © 2017 EAG, INC. | REV. 11.16.18 PAGE 2 OF 6 EAG.COM Thermal Analysis DIFFERENTIAL SCANNING CALORIMETRY (DSC) DESCRIPTION • Resolve subtle, weak or overlapping phase transitions DSC performs quantitative calorimetric measurements on STRENGTHS solid, liquid or semisolid samples. Heat flux DSC measures the • Small sample size difference in temperature (T) between the sample and an inert reference and calculates the quantity of heat flow (q) into or out of • Highly accurate measurement of phase transitions and heat the sample using the equation q = DT/R, where R is the thermal capacities resistance of the transducer (DSC cell). • Very precise temperature control (isothermal holds and DSC Q SeriesTM models (TA Instruments, Inc.) measure absolute heating/cooling ramps) heat flow by application of cell resistance and capacitance • Programmable sequences calibrations. This feature enables the direct measurement of • Sensitive measurement of subtle or weak phase transitions specific heat capacity of a material using a single experiment. The • Ability to separate overlapping thermal transitions Q SeriesTM feature a special operating mode called temperature modulated DSC (MDSC). MDSC applies a sinusoidal temperature LIMITATIONS modulation superimposed over a linear heating rate. MDSC is a • Works best for samples having a surface that spreads powerful technique which makes it possible to measure weak relatively flat against the bottom of the “crucible” or pan. transitions, separate overlapping thermal events and provide highly accurate heat capacity measurements. • Accurate data cannot be obtained when decomposition occurs within the same temperature region as the phase COMMON APPLICATIONS transition (e.g. melting) • Analyze phase transitions and reactions: melting point, • Mass of sample has to remain constant in the pan for accurate crystallization, glass transition, cure temperature, delta H measurement; that means no loss of sample to evaporation or • Measure the heat capacity of pure compounds and mixtures sublimation during the test • Compare quality (QC, failure analysis, new material evaluation) • Identify unknown materials • Evaluate formulations, blends and effects of additives ∆H (T,t) ∆H (T,t) • Determine the effects of aging and evaluate thermal history • Estimate percent crystallinity • Determine percent purity of relatively pure organics • Study cure or crystallization kinetics and effect of impurities on crystallization • Determine phase separation of polymer blends and copolymers • Estimate degree of cure; measure residual cure • Evaluate eutectic point • Characterize polymorphic materials COPYRIGHT © 2017 EAG, INC. | REV. 11.16.18 PAGE 3 OF 6 EAG.COM Thermal Analysis THERMOMECHANICAL ANALYSIS (TMA) DESCRIPTION COMMON APPLICATIONS TMA is used to study physical properties of viscoelastic materials • Determine softening point (Tg) of polymers under mechanical loading as a function of temperature and time. • Measure coefficient of thermal expansion (CTE) of polymers, Measurements are performed in either compression or tension composites, ceramics, inorganics and metals mode by a probe that applies force to the sample. • Characterize CTE differences of polymer in glassy state Typical viscoelastic materials exhibit volume changes with ramping (below Tg) and in rubbery state (above Tg) temperature. As the sample changes dimension, the probe travels • Study effects of physical aging, crosslinking or post-cure on up or down, and the distance of travel is precisely measured by a the Tg of thermoplastics or thermosetting polymers transducer coupled to the probe. The measured change in sample length correlates with such properties as shrinkage, expansion, • Determine dimensional stability of parts at operating swelling and softening. temperature and loading TMA techniques involve selection of the correct probe and • Characterize shrinkage of oriented films conditions to measure the properties of interest. Typical probe • Evaluate differences in shrinkage and expansion of films configurations include: or layered composites as a function of loading direction: • Compression-type force: Probe is placed on top the sample, “machine” and “transverse”, or “in-plane” and “out-of-plane” which is mounted on a platform. Used to monitor expansion, • Force ramp or step force to evaluate changing load on shrinkage or softening based on selection of contact area dimension change (probe tip geometry) and force. • Isostrain: measure the force required to maintain constant • Tension-type force: Film or fiber sample is clamped between strain while material is heated a stationary platform and the probe. Used to measure STRENGTHS expansion, shrinkage and softening. • Small sample size • Low force range F • Force alteration: linear and stepwise • Programmable temperature: (1) sequential heating and ∆L sample cooling cycles, (2) isothermal cool heat LIMITATIONS • Requires parallel faces and uniform thickness for expansion • Reasonably flat samples for penetration COPYRIGHT © 2017 EAG, INC. | REV. 11.16.18 PAGE 4 OF 6 EAG.COM Thermal Analysis DYNAMIC MECHANICAL ANALYSIS (DMA) DESCRIPTION more stationary clamps, which are used to mount the sample. The Polymers respond to the energy
Load more

Recommended publications
  • Conceptual Approach to Thermal Analysis and Its Main Applications
    Prospect. Vol. 15, No. 2, Julio-Diciembre de 2017, 117-125 Conceptual approach to thermal analysis and its main applications Aproximación conceptual al análisis térmico y sus principales aplicaciones Alejandra María Zambrano Arévalo1*, Grey Cecilia Castellar Ortega2, William Andrés Vallejo Lozada3, Ismael Enrique Piñeres Ariza4, María Mercedes Cely Bautista5, Jesús Sigifredo Valencia Ríos6 1*M.Sc. Chemical Sciences, Full Professor, Universidad de la Costa. Barranquilla-Colombia. 2M.Sc. Chemical Sciences, Full Professor, Universidad Autónoma del Caribe. Barranquilla-Colombia. 3Ph.D. Chemical Sciences, Full Professor, Universidad del Atlántico. Barranquilla-Colombia. 4M.Sc. Physical Sciences, Occasional Full Professor, Universidad del Atlántico. Barranquilla-Colombia. 5Ph.D. Engineering, Full Professsor, Universidad Autónoma del Caribe. Barranquilla-Colombia. 6Ph. D. Universidad Nacional de Colombia, Vicerrector Universidad Nacional de Colombia (Sede Palmira). Palmira-Colombia. E-mail: [email protected] Recibido 12/04/2017 Cite this article as: A. Zambrano, G.Castellar, W.Vallejo, I.Piñeres, M.M. Aceptado 28/05/2017 Cely, J.Valencia, Aproximación conceptual al análisis térmico y sus principales aplicaciones, “Conceptual approach to thermal analysis and its main applications”. Prospectiva, Vol 15, N° 2, 117-125, 2017. ABSTRACT This work shows to the reader a general description about the techniques of classic thermal analysis as known as Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA) and Thermal Gravimetric Analysis. These techniques are very used in science and material technologies (metals, metals alloys, ceramics, glass, polymer, plastic and composites) with the purpose of characterizing precursors, following and control of process, adjustment of operation conditions, thermal treatment and verifying of quality parameters. Key words: Physical chemistry; Calorimetry; Thermochemistry; Thermal analysis.
    [Show full text]
  • Beam Sterilization with Gamma Radiation Sterilization
    FABAD J. Pharm. Sci., 34, 43–53, 2009 REVIEW ARTICLE Sterilization Methods and the Comparison of E-Beam Sterilization with Gamma Radiation Sterilization Mine SİLİNDİR*, A. Yekta ÖZER*° Sterilization Methods and the Comparison of E-Beam Sterilizasyon Metodları ve E-Demeti ile Sterilizasyonun Sterilization with Gamma Radiation Sterilization Gama Radyasyonu ile Karşılaştırılması Summary Özet Sterilization is used in a varity of industry field and a strictly Sterilizasyon endüstrinin pek çok alanında kullanılmakta- required process for some products used in sterile regions dır ve medikal cihazlar ve parenteral ilaçlar gibi direk vü- of the body like some medical devices and parenteral drugs. cudun steril bölgelerine uygulanan bazı ürünler için ge- Although there are many kinds of sterilization methods rekli bir işlemdir. Ürünlerin fizikokimyasal özelliklerine according to physicochemical properties of the substances, bağlı olarak pek çok farklı sterilizasyon metodu bulunma- the use of radiation in sterilization has many advantages sına rağmen, radyasyonun sterilizasyon amacıyla kullanı- depending on its substantially less toxicity. The use of mı daha az toksik etkisine bağlı olarak pek çok avantaja sa- radiation in industrial field showed 10-15% increase per every hiptir. Radyasyonun endüstriyel alanda kullanımı her yıl year of the previous years and by 1994 more than 180 gamma bir öncekine oranla %10-15 artış göstermiştir ve 1994’ten irradiation institutions have functioned in 50 countries. As bu yana 50 ülkede 180’den fazla gama ışınlama
    [Show full text]
  • Thermal Analysis Methods
    Modern Methods in Heterogeneous Catalysis Research Thermal analysis methods Rolf Jentoft 03.11.06 Outline • Definition and overview • Thermal Gravimetric analysis • Evolved gas analysis (calibration) • Differential Thermal Analysis/DSC • Kinetics introduction • Data analysis examples Definition Thermal analysis: the measurement of some physical parameter of a system as a function of temperature. Usually measured as a dynamic function of temperature. Types of thermal analysis – TG (Thermogravimetric) analysis: weight – DTA (Differential Thermal Analysis): temperature – DSC (Differential Scanning Calorimetry): temperature – DIL (Dilatometry): length – TMA (Thermo Mechanical Analysis): length (with strain) – DMA (Dynamic-Mechanical Analysis): length (dynamic) – DEA (Dielectric Analysis): conductivity – Thermo Microscopy: image –...– Combined methods Thermogravimetric Developed by Honda in 1915 Oven Oven heated at controlled rate Sample Temperature and Weight are recorded Balance Types of thermal analysis – TG (Thermogravimetric) analysis: weight – DTA (Differential Thermal Analysis): temperature – DSC (Differential Scanning Calorimetry): temperature – DIL (Dilatometry): length – TMA (Thermo Mechanical Analysis): length (with strain) – DMA (Dynamic-Mechanical Analysis): length (dynamic) – DEA (Dielectric Analysis): conductivity – Thermo Microscopy: image – Combined methods DTA/DSC First introduced by Le Chatelier in 1887, perfected by Roberts-Austen 1899 Sample Reference Oven heated at controlled rate Temperature and temperature difference
    [Show full text]
  • Differential Scanning Calorimetry Beginner's Guide
    FREQUENTLY ASKED Differential Scanning QUESTIONS Calorimetry (DSC) DSC 4000 DSC 8000 DSC 8500 with Autosampler DSC 6000 with Autosampler PerkinElmer's DSC Family A Beginner's Guide This booklet provides an introduction to the concepts of Differential Scanning Calorimetry (DSC). It is written for the materials scientist unfamiliar with DSC. The differential scanning calorimeter (DSC) is a fundamental tool in thermal analysis. It can be used in many industries – from pharmaceuticals to polymers and from nanomaterials to food products. The information these instruments generate is used to understand amorphous and crystalline behavior, poly- morph and eutectic transitions, curing and degree of cure, and many other material properties used to design, manufacture and test products. DSCs are manufactured in several variations, but PerkinElmer is the only company to make both single and double-furnace styles. We’ve manufactured thermal analysis instrumentation since 1960, and no one understands the applications of DSC like we do. In the following pages, we answer common questions about what a DSC is, how the instruments work, and what they tell you. Table of Contents 20 Common Questions about DSC What is DSC? ................................................................................................3 What is the difference between a heat flow and a heat flux DSC? ...................3 How does the difference affect me? ..............................................................3 Why do curves point in different directions? ...................................................4
    [Show full text]
  • THERMAL ANALYSIS New Castle, DE USA
    THERMAL ANALYSIS New Castle, DE USA Lindon, UT USA Hüllhorst, Germany Shanghai, China Beijing, China Tokyo, Japan Seoul, South Korea Taipei, Taiwan Bangalore, India Sydney, Australia Guangzhou, China Eschborn, Germany Wetzlar, Germany Brussels, Belgium Etten-Leur, Netherlands Paris, France Elstree, United Kingdom Barcelona, Spain Milano, Italy Warsaw, Poland Prague, Czech Republic Sollentuna, Sweden Copenhagen, Denmark Chicago, IL USA São Paulo, Brazil Mexico City, Mexico Montreal, Canada Thermal Analysis Thermal Analysis is important to a wide variety of industries, including polymers, composites, pharmaceuticals, foods, petroleum, inorganic and organic chemicals, and many others. These instruments typically measure heat flow, weight loss, dimension change, or mechanical properties as a function of temperature. Properties characterized include melting, crystallization, glass transitions, cross-linking, oxidation, decomposition, volatilization, coefficient of thermal expansion, and modulus. These experiments allow the user to examine end-use performance, composition, processing, stability, and molecular structure and mobility. All TA Instruments thermal analysis instruments are manufactured to exacting standards and with the latest technology and processes for the most accurate, reliable, and reproducible data available. Multiple models are available based on needs; suitable for high sensitivity R&D as well as high throughput quality assurance. Available automation allows for maximum unattended laboratory productivity in all test environments.
    [Show full text]
  • Dynamic Mechanical Analysis: a Practical Introduction
    DYNAMIC MECHANICAL ANALYSIS A Practical Introduction Kevin P. Menard CRC Press Boca Raton London New York Washington, D.C. Library of Congress Cataloging-in-Publication Data Menard, Kevin Peter Dynamic mechanical analysis : a practical introduction / by Kevin P. Menard. p. cm. Includes bibliographical references. ISBN 0-8493-8688-8 (alk. paper) 1. Polymers—Mechanical properties. 2. Polymers—Thermal properties. I. Title. TA455.P58M45 1999 620.1¢9292—dc21 98-53025 CIP This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the authors and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage or retrieval system, without prior permission in writing from the publisher. The consent of CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC, 2000 N.W. Corporate Blvd., Boca Raton, Florida 33431. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Visit the CRC Press Web site at www.crcpress.com © 1999 by CRC Press LLC No claim to original U.S.
    [Show full text]
  • Thermogravimetric Analysis
    Experimental Techniques in Thermal Analysis Thermogravimetry (TG) & Differential Scanning Calorimetry (DSC) Debjani Banerjee Department of Chemical Engineering IIT Kanpur Instrumentation facilities in PGRL, CHE 1) Simultaneous Thermogravimetry and Differential Scanning Calorimetry (SDT Q600- TA Instruments) 2) Autosorb iQ- Physisorption, Chemisorption, Temperature Programmed Reduction (TPR), Temperature Programmed Oxidation (TPO) & Temperature Programmed Desorption (TPD) set up (Quantachrome India) 3) Inductively Coupled Mass Spectrometry (ICPMS)-Trace metal concentration upto ppb levels (Agilent) 4) Atomic Absorption Spectroscopy (AAS) (Agilent) 5) Powder X-ray Diffractometer- with separate optical attachment to observe diffraction in thin films (PanAnalytical). 6) Field Emission Scanning Electron Microscope (TESCAN) 7) Nano- IR (AFM+IR) (Anasys Instrument) 8) Multichannel and Single Channel Voltametry (MVA) (Metrohm) 9) Flow Cytometer (Partec-Sysmex) 10) Universal Testing Machine (UTM) (Zwick/Roell) 11) MicroPIV Thermal analysis General conformation of Thermal Analysis Apparatus Physical property measuring sensor, a controlled-atmosphere furnace, a temperature programmer – all interfaced to a computer TGA, Basics Dynamic TGA Isothermal TGA What TGA Can Tell You? Thermal Stability of Materials: Explicate decomposition mechanism, fingerprint materials for identification & quality control Oxidative Stability of Materials: Oxidation of metals in air, Oxidative decomposition of organic substances in air/O2, Thermal decomposition in inert
    [Show full text]
  • A Teaching Tool
    INTRODUCTION TO PHARMACEUTICAL THERMAL ANALYSIS: A TEACHING TOOL SHRAVAN SINGH THAKUR Bachelor of Science in Pharmacy OSMANIA UNIVERSITY May, 2007 Submitted in partial fulfillment of requirements for the degree MASTER OF SCIENCE IN CHEMISTRY At the CLEVELAND STATE UNIVERSITY August, 2011 This thesis has been approved for the Department of CHEMISTRY and the College of Graduate Studies by __________________________________________ “Thesis Chairperson”, Dr. Bin Su _______________________________________ Co-chair, Dr. Alan.T Riga ________________________________________ Dr. Stan Duraj ______________________________________ Dr. Robert Wei Date: July 27, 2011 ACKNOWLEDGEMENTS Foremost, I would like to express my deep and sincere gratitude to my advisor Dr. Alan Riga for the continuous support for my Master’s thesis research, for his patience, motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. His wide knowledge and his logical way of thinking lead me working on diverse exciting projects. His understanding, encouraging and personal guidance have provided a good basis for the present thesis. Besides my advisor, I would like to thank the rest of my thesis committee members, Dr. Bin Su, Dr. Stan Duraj, and Dr. Robert Wei for their encouragement and insightful comments. I am indebted to all of my colleagues, Dr. Indika Perera, M. Ellen Matthews, Lakshmi Kaza, Manik Pavan Maheswaram, Hareesha Venumuddala and Dhruthiman Mantheni for their support in writing the thesis and stimulating discussions. Last but not the least; I would like to thank my parents for supporting me spiritually throughout my life. Without their financial support and understanding it would have been impossible for me to finish this work.
    [Show full text]
  • Dynamic Mechanical Analysis of Food Products, TA-119
    Thermal Analysis & Rheology Thermal Analysis Application Brief Dynamic Mechanical Analysis of Food Products Number TA-119 SUMMARY lengths (from <1 mm up to 65 mm). In addition, a variety of clamping configurations is available to accommodate differ- The processing and handling of food products can signifi- ent material types. An electromagnetic motor attached to one cantly affect the material's texture, flavor, and appearance. arm drives the arm/sample to a strain (amplitude) selected by Historically, the methods used to evaluate and/or predict the operator. As the arm/sample system is displaced, the these properties have been somewhat arbitrary and non- sample undergoes flexural deformation. A linear variable quantitative. The use of analytical instrument techniques differential transformer (LVDT) mounted on the driven arm such as thermal analysis provides a more quantitative, repro- measures the sample's response to the applied stress and uses ducible way for characterizing food products. Dynamic Me- that information to calculate the modulus and damping prop- chanical Analysis (DMA), for example, can provide informa- erties of the material. The rate of deformation (frequency) can tion about the mechanical properties of food and how they are be selected by the operator from a wide range (0.001 to 10 affected by various processing conditions. Hertz). A frequency of 1 hertz is often used to provide the best INTRODUCTION compromise between sensitivity and time of analysis. Dynamic Mechanical Analysis (DMA) is a sensitive and Samples of a commercially packaged white bread were ex- o versatile thermal analysis technique which measures the posed to atmosphere (temperature ca. 23 C and ca.
    [Show full text]
  • Crystallization of Polymers Investigated by Temperature-Modulated DSC
    materials Review Crystallization of Polymers Investigated by Temperature-Modulated DSC Maria Cristina Righetti National Research Council of Italy—Institute for Chemical and Physical Processes (CNR-IPCF), Via Moruzzi 1, 56124 Pisa, Italy; [email protected]; Tel.: +39-050-315-2068 Academic Editor: Ming Hu Received: 6 March 2017; Accepted: 10 April 2017; Published: 24 April 2017 Abstract: The aim of this review is to summarize studies conducted by temperature-modulated differential scanning calorimetry (TMDSC) on polymer crystallization. This technique can provide several advantages for the analysis of polymers with respect to conventional differential scanning calorimetry. Crystallizations conducted by TMDSC in different experimental conditions are analysed and discussed, in order to illustrate the type of information that can be deduced. Isothermal and non-isothermal crystallizations upon heating and cooling are examined separately, together with the relevant mathematical treatments that allow the evolution of the crystalline, mobile amorphous and rigid amorphous fractions to be determined. The phenomena of ‘reversing’ and ‘reversible‘ melting are explicated through the analysis of the thermal response of various semi-crystalline polymers to temperature modulation. Keywords: polymer; crystallization; differential scanning calorimetry; temperature-modulated differential scanning calorimetry; reversing melting; reversible melting; crystalline fraction; mobile amorphous fraction; rigid amorphous fraction 1. Introduction Temperature-modulated
    [Show full text]
  • Thermal Analysis TGA / DTA
    Thermal Analysis TGA / DTA Linda Fröberg Outline Definitions What is thermal analysis? Instrumentation & origin of the TGA-DTA signal. TGA Basics and applications DTA Phase diagrams & Thermal analysis • Thermal analysis,an experimental method to determine phase diagrams. Nomenclature of Thermal Analysis ICTAC (International Confederation for Thermal Analysis and Calorimetry) Definition of the field of Thermal Analysis (TA) Thermal Analysis (TA) is a group of techniques that study the properties of materials as they change with temperature Thermal analysis In practice thermal analysis gives properties like; enthalpy, thermal capacity, mass changes and the coefficient of heat expansion. Solid state chemistry uses thermal analysis for studying reactions in the solid state, thermal degradation reactions, phase transitions and phase diagrams. Thermal analysis ... Includes several different methods. These are distinguished from one another by the property which is measured. Thermogravimetric analysis (TGA): mass Differential thermal analysis (DTA): temperature difference Differential scanning calorimetry (DSC): heat difference Pressurized TGA (PTGA): mass changes as function of pressure. Thermo mechanical analysis (TMA): deformations and dimension Dilatometry (DIL): volume Evolved gas analysis (EGA): gaseous decomposition products Often different properties may be measured at the same time: TGA-DTA, TGA-EGA Instrumentation & origin of the TGA-SDTA signal TGA - SDTA Mettler - Toledo A modern TGA - DTA Leena Hupa & Daniel Lindberg Furnace components Heating resistor Rective purge gas inlet Balance arm Furnace thermoelement Heating resistor Sample crucible Sample holder sDTA thermoelement Operating range: Heating rate: Typical heating rate: - 200 - 1600 ºC up to 100 ºC/min 10 – 20 ºC/min Heat transfer from crucible to recording microbalance & thermo elements platinum Origin of the TGA-DTA signal Schematic diagram showing the different temperatures in the DTA during a thermal process.
    [Show full text]
  • Laboratory Experiments in Thermal Analysis of Polymers for a Senior/Graduate Level Materials Science Course
    AC 2010-2182: LABORATORY EXPERIMENTS IN THERMAL ANALYSIS OF POLYMERS FOR A SENIOR/GRADUATE LEVEL MATERIALS SCIENCE COURSE Michael Kessler, Iowa State University Michael Kessler is an Assistant Professor of Materials Science and Engineering at Iowa State University. His research interests include the mechanics and processing of polymers and polymer matrix composites, thermal analysis, fracture mechanics, and biologically inspired materials. Prashanth Badrinarayanan, Iowa State University Prashanth Badrinarayanan is a Postdoctoral Research Associate in the Department of Materials Science and Engineering at Iowa State University. His research interests include development and characterization of multifunctional polymer matrix nanocomposites and bio-based resins, and investigation of the glass transition phenomena in amorphous polymers and polymer blends using experimental and computational techniques. Page 15.830.1 Page © American Society for Engineering Education, 2010 Laboratory Experiments in Thermal Analysis of Polymers for a Senior/Graduate Level Materials Science Course Abstract In the lab accompanying a senior/graduate level Physical and Mechanical Properties of Polymers course, five new lab experiments in thermal analysis of polymers were developed to supplement the classroom lectures and the existing lab exercises. One of these experiments used a new, state-of-the-art rapid heating and cooling differential scanning calorimeter (DSC) to investigate the effects of heating rate and isothermal annealing conditions on the thermal behavior of poly(ethylene terphthalate) (PET). This unique lab experiment was very successful with the students and, because of the high heating and cooling rates, the students were able to perform many experiments within the two hour lab. In this paper we discuss the implementation of these new thermal analysis labs in the course, with an emphasis in comparing the traditional DSC lab with the rapid heating/cooling DSC lab.
    [Show full text]