DOCSLIB.ORG

The Crystallization of Poly(Ethylene Terephthalate) Studied By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Crystallization of Poly(Ethylene Terephthalate) Studied By The Crystallization of Poly(ethylene terephthalate) Studied by Thermal Analysis and FTIR Spectroscopy ZIYU CHEN A thesis submitted to the University of Birmingham For the degree of Doctor of Philosophy School of Metallurgy and Materials College of Engineeting and Physical Sciences University of Birmingham December 2012 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Synopsis This thesis concerns the thermal behaviour and properties, isothermal crystallization kinetics and seeded crystallization study of poly(ethylene terephthalate) (PET) using thermal analysis Fourier transform infrared spectroscopy (TA-FTIR), two-dimensional infrared correlation spectroscopy (2D-FTIR) and differential scanning calorimetry (DSC). TA-FTIR has been used to characterize phase transitions by a change in the absorbance or peak position with temperature in thermal cycling. It provides more information in assigning the phase transition temperature to an individual chain segment rather than other TA techniques. It also observes two different types of thermal behaviours, Type I and Type II, of the functional groups during thermal treatment. The most significant achievement of this project assign to find out that the carbonyl stretching band has an amorphous band at 1727 cm-1 in the melt and a crystalline band at 1717 cm-1 by TA-FTIR. It was then successfully analyzed by 2D correlation spectroscopy and presented “angel” pattern and two cross peaks on synchronous and asynchronous correlation spectra respectively. i The isothermal crystallization kinetics of PET were measured from 230 to 240oC by FTIR focusing on the carbonyl ester group. The deconvolution of the 1727 and 1717 cm-1 overlapping absorption bands makes it possible to analyze the kinetics of both primary and secondary crystallization by Avrami equations. The Avrami exponents n were determined as 2.0 for primary and 1.0 for secondary process. Melting behaviour studies were carried out by DSC observing that crystallinity, melting temperature and calculated lamellar thickness of PET increase with the extending time period of isothermal crystallization in secondary process. Seeded crystallization provides for the possibility of crystallizing polymers at higher temperatures, even located in the normal melting temperature region, to produce greater lamellae thicknesses and higher melting temperature and to consider the effect of this morphology on their mechanical and physical properties. However, the mechanism of growth rate of seeded crystallization is questionable that requires further research. ii Acknowledgement Firstly, I sincerely appreciate my supervisors Prof. James N. Hay and Dr. Michel J. Jenkins. I am deeply indebted their patient guidance, profound expertise and wisdom throughout these years. They were always willing to answer my questions, provide valuable advice and support in difficulty during the study. I feel extremely honoured to work under their great guidance. Without their help and support, this work would never have been accomplished. I would like to give a very special thanks to Mr. Frank Biddlestone for his technical support. His broad experience, logical way of thinking and constructive comment has been of great value for me in doing the experimental part of the research. I am deeply grateful to all my colleagues and friends for supports, sharing their knowledge and precious friendship that made my life in UK enjoyable in these years. Especially to Dr. Abdul G. AL Lafi, Dr Samsudin S. Amril, Dr. Jin Tang, Dr. ZhenHua Hu and Dr. DeJing Kong. The most important, I would above all like to thank my parents. Their endless love, support and truth is my motivity helping me through the time of this degree and I can never thank them enough. Finally to my fiancée Yi Huang, thank you for your love, understanding, encouragement that support me over this period. iii Contents CHAPTER ONE: INTRODUCTION ...................................................................... 1 1.1 POLY (ETHYLENE TEREPHTHALATE) ................................................................................................... 1 1.1.1 Production of PET ........................................................................................................... 2 1.1.2 Commercial Uses of PET. ............................................................................................... 3 1.2 KINETICS OF POLYMER CRYSTALLIZATION .......................................................................................... 5 1.2.1 Polymer crystallization .................................................................................................. 5 1.2.2 Nucleation. ..................................................................................................................... 6 1.2.3 Crystal Growth. .............................................................................................................. 9 1.2.4 The temperature Dependence of Growth Rate........................................................... 10 1.2.5 The Avrami Equation. .................................................................................................. 15 1.3 MORPHOLOGY OF CRYSTALLINE POLYMERS .................................................................................... 16 1.3.1 Single crystals .............................................................................................................. 16 1.3.2 Spherulites ................................................................................................................... 18 1.4 THE MELTING OF POLYMERS. ....................................................................................................... 22 1.5 AIMS AND OBJECTIVES OF THE PROJECT. ........................................................................................ 24 CHAPTER TWO: MATERIALS, EXPERIMENTAL TECHNIQUES AND PROCEDURES ........................................................................................................ 26 26 2.1 MATERIALS. .............................................................................................................................. 26 2.1.1 Poly(ethylene terephthalate) (PET). ............................................................................ 26 2.2 EXPERIMENTAL TECHNIQUES AND PROCEDURES. .............................................................................. 27 2.2.1 Infrared Spectroscopy. ................................................................................................. 27 2.2.1.1 Introduction ........................................................................................................................... 27 2.2.1.2 Experimental Procedures. ...................................................................................................... 31 2.2.1.3 Peak Resolution in a FTIR Spectrum. ...................................................................................... 35 2.2.2 Differential Scanning Calorimetry (DSC). .................................................................... 40 2.2.2.1 Introduction. .......................................................................................................................... 40 iv 2.2.2.2 Experimental Procedures. ...................................................................................................... 42 2.2.3 Hot-stage Microscopy. ................................................................................................. 45 2.2.3.1 Optical Microscopy. ............................................................................................................... 45 2.2.3.2 Hot-stage Microscopy. ........................................................................................................... 45 2.2.3.3 Experimental Procedures. ...................................................................................................... 46 CHAPTER THREE: THERMAL ANALYSIS OF PET BY DSC AND FTIR SPECTROSCOPY ................................................................................................... 48 3.1 INTRODUCTION. ......................................................................................................................... 48 3.2 DSC THERMAL ANALYSIS OF PET. ................................................................................................. 50 3.3 TYPICAL FTIR SPECTRUM OF PET.................................................................................................. 54 3.4 THERMAL ANALYSIS PET ON FTIR SPECTRUM. ................................................................................ 55 3.4.1 On cooling PET from the Melt. .................................................................................... 55 3.4.2 The Effect of Thermal Cycling on the FTIR Spectra ..................................................... 56 3.4.3 Type l Behaviour. ......................................................................................................... 59 3.4.4 Type II Behaviour. .......................................................................................................
Load more

Recommended publications
  • 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.
    [Show full text]
  • Polymer Dynamics
    Polymer Dynamics 2017 School on Soft Matters and Biophysics Instructor: Alexei P. Sokolov, e-mail: [email protected] Text: Instructor's notes with supplemental reading from current texts and journal articles. Please, have the notes printed out before each lecture. Books (optional): M.Doi, S.F.Edwards, “The Theory of Polymer Dynamics”. Y.Grosberg, A.Khokhlov, “Statistical Physics of Macromolecules”. J.Higgins, H.Benoit, “Polymers and Neutron Scattering”. 1 Course Content: I. Introduction II. Experimental methods for analysis of molecular motions III. Vibrations IV. Fast and Secondary Relaxations V. Segmental Dynamics and Glass Transition VI. Chain Dynamics and Viscoelastic Properties VII. Rubber Elasticity VIII. Concluding Remarks 2 INTRODUCTION Polymers are actively used in many technologies Traditional technologies: Even better perspectives for use in novel technologies: Example: Light-weight materials Boeing-787 “Dreamliner” 80% by volume is plastic Materials for energy generation Example: polymer solar cells Materials for energy storage Example: Polymer-based Li battery Polymers have huge potential for applications in Bio-medical field “Smart” materials, stimuli-responsive, self-healing … 3 Polymers Polymers are long molecules They are constructed by covalently bonded structural units – monomers Main difference between properties of small molecules and polymers is related to the chain connectivity Advantages of Polymeric Based Materials: Easy processing, relatively cheap manufacturing Light weight (contain mostly light elements like C, H, O) Unique viscoelastic properties (e.g. rubber elasticity) Extremely broad tunability of macroscopic properties 4 Definitions o Monomer – repeat unit, structural block of the polymer chain o Oligomer – short chains, ~ 3-10 monomers o Polymers – long chains, usually hundreds of monomers o Degree of polymerization – number of monomers in the polymer chain Molecular weight: Weight of the molecule M [g/mol].
    [Show full text]
  • Biodegradable Polymeric Biomaterials in Different Forms for Long-Acting
    University of Tennessee Health Science Center UTHSC Digital Commons Theses and Dissertations (ETD) College of Graduate Health Sciences 5-2017 Biodegradable Polymeric Biomaterials in Different Forms for Long-acting Contraception and Drug Delivery to the Eye and Brain Dileep Reddy Janagam University of Tennessee Health Science Center Follow this and additional works at: https://dc.uthsc.edu/dissertations Part of the Pharmaceutics and Drug Design Commons Recommended Citation Janagam, Dileep Reddy (http://orcid.org/0000-0002-7235-7709), "Biodegradable Polymeric Biomaterials in Different Forms for Long-acting Contraception and Drug Delivery to the Eye and Brain" (2017). Theses and Dissertations (ETD). Paper 425. http://dx.doi.org/10.21007/etd.cghs.2017.0429. This Dissertation is brought to you for free and open access by the College of Graduate Health Sciences at UTHSC Digital Commons. It has been accepted for inclusion in Theses and Dissertations (ETD) by an authorized administrator of UTHSC Digital Commons. For more information, please contact [email protected]. Biodegradable Polymeric Biomaterials in Different Forms for Long-acting Contraception and Drug Delivery to the Eye and Brain Document Type Dissertation Degree Name Doctor of Philosophy (PhD) Program Pharmaceutical Sciences Track Pharmaceutics Research Advisor Tao L. Lowe, Ph.D. Committee Joel Bumgardner, Ph.D. James R. Johnson, Ph.D. Bernd Meibohm, Ph.D. Duane D. Miller, Ph.D. ORCID http://orcid.org/0000-0002-7235-7709 DOI 10.21007/etd.cghs.2017.0429 Comments Two year embargo expires
    [Show full text]
  • 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]
  • Lecture Notes on Structure and Properties of Engineering Polymers
    Structure and Properties of Engineering Polymers Lecture: Microstructures in Polymers Nikolai V. Priezjev Textbook: Plastics: Materials and Processing (Third Edition), by A. Brent Young (Pearson, NJ, 2006). Microstructures in Polymers • Gas, liquid, and solid phases, crystalline vs. amorphous structure, viscosity • Thermal expansion and heat distortion temperature • Glass transition temperature, melting temperature, crystallization • Polymer degradation, aging phenomena • Molecular weight distribution, polydispersity index, degree of polymerization • Effects of molecular weight, dispersity, branching on mechanical properties • Melt index, shape (steric) effects Reading: Chapter 3 of Plastics: Materials and Processing by A. Brent Strong https://www.slideshare.net/NikolaiPriezjev Gas, Liquid and Solid Phases At room temperature Increasing density Solid or liquid? Pitch Drop Experiment Pitch (derivative of tar) at room T feels like solid and can be shattered by a hammer. But, the longest experiment shows that it flows! In 1927, Professor Parnell at UQ heated a sample of pitch and poured it into a glass funnel with a sealed stem. Three years were allowed for the pitch to settle, and in 1930 the sealed stem was cut. From that date on the pitch has slowly dripped out of the funnel, with seven drops falling between 1930 and 1988, at an average of one drop every eight years. However, the eight drop in 2000 and the ninth drop in 2014 both took about 13 years to fall. It turns out to be about 100 billion times more viscous than water! Pitch, before and after being hit with a hammer. http://smp.uq.edu.au/content/pitch-drop-experiment Liquid phases: polymer melt vs.
    [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]
  • Lecture1541230922.Pdf
    MODULE-1 Introduction: -The macromolecules are divided between biological and non-biological materials. The biological polymers form the very foundation of life and intelligence, and provide much of the food on which man exists. The non-biological polymers are primarily the synthetic materials used for plastics, fibers and elastomers but a few naturally occurring polymers such as rubber wool and cellulose are included in this class. Today these substances are truly indispensable to mankind because these are essential to his clothing,shelter, transportation, communication as well as the conveniences of modern living. Polymer Biological Non- biological Proteins, starch, wool plastics, fibers easterners Note: Polymer is not said to be as macromolecule, because polymer is composedof repeating units whereas the macromolecules may not be composed of repeating units. Definition: A polymer is a large molecule built up by the repetition of small, simple chemical units known as repeating units which are held together by chemical covalent bonds. These repeating units are called monomer Polymer – ---- poly + meres Many parts In some cases, the repetition is linear but in other cases the chains are branched on interconnected to form three dimensional networks. The repeating units of the polymer are usually equivalent on nearly equivalent to the monomer on the starting material from which the polymer is formed. A higher polymer is one in which the number of repeating units is in excess of about 1000 Degree of polymerization (DP): - The no of repeating units or monomer units in the chain of a polymer is called degree of polymerization (DP) . The molecular weight of an addition polymer is the product of the molecular weight of the repeating unit and the degree of polymerization (DP).
    [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]