SIST EN ISO 11357-1:2010
(Main)Plastics - Differential scanning calorimetry (DSC) - Part 1: General principles (ISO 11357-1:2009)
Plastics - Differential scanning calorimetry (DSC) - Part 1: General principles (ISO 11357-1:2009)
ISO 11357 specifies several differential scanning calorimetry (DSC) methods for the thermal analysis of polymers and polymer blends, such as - thermoplastics (polymers, moulding compounds and other moulding materials, with or without fillers, fibres or reinforcements); - thermosets (uncured or cured materials, with or without fillers, fibres or reinforcements); - elastomers (with or without fillers, fibres or reinforcements). ISO 11357 is intended for the observation and measurement of various properties of, and phenomena associated with, the above-mentioned materials, such as - physical transitions (glass transition, phase transitions such as melting and crystallization, polymorphic transitions, etc.); - chemical reactions (polymerization, crosslinking and curing of elastomers and thermosets, etc.); - the stability to oxidation; - the heat capacity. This part of ISO 11357 specifies a number of general aspects of differential scanning calorimetry, such as the principle and the apparatus, sampling, calibration and general aspects of the procedure and test report common to all following parts. Details on performing specific methods are given in subsequent parts of ISO 11357 (see Foreword).
Kunststoffe - Dynamische Differenz-Thermoanalyse (DSC) - Teil 1: Allgemeine Grundlagen (ISO 11357-1:2009)
Die vorliegende Internationale Norm legt Verfahren der Dynamischen Differenz-Thermoanalyse (DSC) zur
thermischen Analyse von Polymeren und Polymermischungen fest, wie z. B. von
- Thermoplasten (Polymeren, Formmassen und Produkten des Formpressens mit oder ohne Füllstoff(e),
Fasern oder Verstärkungszusatzstoffe),
- Duroplasten (gehärteten oder ungehärteten Materialien mit oder ohne Füllstoff(e), Fasern oder
Verstärkungszusatzstoffe),
- Elastomeren (mit oder ohne Füllstoff(e), Fasern oder Verstärkungszusatzstoffe).
Die vorliegende Internationale Norm wird zwecks Beobachtung und quantitativer Erfassung verschiedener
Erscheinungen oder Eigenschaften der oben genannten Materialien angewendet, wie z. B.
- physikalischer Umwandlungen (Glasübergang, Phasenumwandlungen wie Schmelzen oder Kristallisation,
polymorphen Umwandlungen usw.),
- chemischer Reaktionen (Polymerisation, Vernetzung und Vulkanisation von Elastomeren und
Duroplasten usw.),
- Oxidationsstabilität,
- Wärmekapazität.
Teil 1 dieser Internationalen Norm legt allgemeine Grundsätze der dynamischen Differenz-Thermoanalyse
fest, wie z. B. Kurzbeschreibung des Verfahrens und der Geräte, Probenahme, Kalibrierung sowie allgemeine
Aspekte des Verfahrens und des Prüfberichts, die allen darauf folgenden Teilen gemeinsam sind.
Einzelheiten zur Durchführung spezifischer Verfahren sind in nachfolgenden Teilen dieser Internationalen
Norm (siehe Vorwort) angegeben.
Plastiques - Analyse calorimétrique différentielle (DSC) - Partie 1: Principes généraux (ISO 11357-1:2009)
L'ISO 11357 spécifie plusieurs méthodes d'analyse calorimétrique différentielle (DSC) pour l'analyse thermique des polymères et des mélanges de polymères tels que
thermoplastiques (polymères, composants pour moulage et produits pour moulage avec ou sans charge(s), fibres ou additifs de renforcement),
thermodurcissables (matériaux non durcis ou durcis avec ou sans charge(s), fibres ou additifs de renforcement),
élastomères (avec ou sans charge(s), fibres ou additifs de renforcement).
L'ISO 11357 s'applique pour l'observation et la quantification de différents phénomènes ou propriétés des matériaux susmentionnés tels que
les transitions physiques (transition vitreuse, transitions de phases telles que la fusion et la cristallisation, les transitions polymorphes, etc.),
les réactions chimiques (polymérisation, réticulation et durcissement des élastomères et des thermodurcissables, etc.),
la stabilité à l'oxydation,
la capacité thermique.
L'ISO 11357-1:2009 établit les aspects généraux de l'analyse calorimétrique différentielle tels que le principe et l'appareillage, l'échantillonnage, l'étalonnage et les aspects généraux du mode opératoire et du rapport d'essai communs à toutes les parties suivantes.
Les détails relatifs à la réalisation des méthodes spécifiques sont donnés dans les autres parties de l'ISO 11357.
Polimerni materiali - Diferenčna dinamična kalorimetrija (DSC) - 1. del: Splošna načela (ISO 11357-1:2009)
ISO 11357 določa več metod za diferenčno dinamično kalorimetrijo (DSC) za termično analizo polimerov in polimernih mešanic, kot so - termoplasti (polimeri, spojine in drugi materiali za ulivanje s polnili, vlakni ali ojačitvami ali brez njih); - duroplasti (nesušeni ali sušeni materiali s polnili, vlakni ali ojačitvami ali brez njih); - elastomeri (s polnili, vlakni ali ojačitvami ali brez njih). ISO 11357 je namenjen opazovanju in merjenju različnih lastnosti zgoraj navedenih materialov in z njimi povezanih pojavov, kot so – fizikalni prehodi (točka posteklenitve, fazni prehodi, kot sta taljenje in kristalizacija, polimorfni prehodi itd.); - kemične reakcije (polimerizacija, zamreževanje in sušenje elastomerov in duroplastov, itd.); - obstojnost pri oksidaciji; - toplotna kapaciteta. Ta del ISO 11357 določa število splošnih značilnosti diferenčne dinamične kalorimetrije, kot so načelo in aparat, vzorčenje, kalibracija in splošne značilnosti postopka in poročil o preskusih, ki so skupne vsem sledečim delom. Podrobnosti o izvajanju specifičnih metod so navedene v naslednjih delih ISO 11357 (glej Predgovor).
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11357-1:2010
01-januar-2010
1DGRPHãþD
SIST EN ISO 11357-1:1999
3ROLPHUQLPDWHULDOL'LIHUHQþQDGLQDPLþQDNDORULPHWULMD '6& GHO 6SORãQD
QDþHOD ,62
Plastics - Differential scanning calorimetry (DSC) - Part 1: General principles (ISO 11357
-1:2009)
Kunststoffe - Dynamische Differenz-Thermoanalyse (DSC) - Teil 1: Allgemeine
Grundlagen (ISO 11357-1:2009)
Plastiques - Analyse calorimétrique différentielle (DSC) - Partie 1: Principes généraux
(ISO 11357-1:2009)
Ta slovenski standard je istoveten z: EN ISO 11357-1:2009
ICS:
17.200.10 Toplota. Kalorimetrija Heat. Calorimetry
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 11357-1:2010 de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 11357-1:2010
---------------------- Page: 2 ----------------------
SIST EN ISO 11357-1:2010
EUROPEAN STANDARD
EN ISO 11357-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2009
ICS 83.080.01 Supersedes EN ISO 11357-1:1997
English Version
Plastics - Differential scanning calorimetry (DSC) - Part 1:
General principles (ISO 11357-1:2009)
Plastiques - Analyse calorimétrique différentielle (DSC) - Kunststoffe - Dynamische Differenz-Thermoanalyse (DSC)
Partie 1: Principes généraux (ISO 11357-1:2009) - Teil 1: Allgemeine Grundlagen (ISO 11357-1:2009)
This European Standard was approved by CEN on 17 September 2009.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11357-1:2009: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 11357-1:2010
EN ISO 11357-1:2009 (E)
Contents Page
Foreword .3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 11357-1:2010
EN ISO 11357-1:2009 (E)
Foreword
This document (EN ISO 11357-1:2009) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics”, the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by April 2010, and conflicting national standards shall be withdrawn at the
latest by April 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11357-1:1997.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 11357-1:2009 has been approved by CEN as a EN ISO 11357-1:2009 without any
modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 11357-1:2010
---------------------- Page: 6 ----------------------
SIST EN ISO 11357-1:2010
INTERNATIONAL ISO
STANDARD 11357-1
Second edition
2009-10-15
Plastics — Differential scanning
calorimetry (DSC) —
Part 1:
General principles
Plastiques — Analyse calorimétrique différentielle (DSC) —
Partie 1: Principes généraux
Reference number
ISO 11357-1:2009(E)
©
ISO 2009
---------------------- Page: 7 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Basic principles .8
4.1 General .8
4.2 Heat-flux DSC.8
4.3 Power-compensation DSC.8
5 Apparatus and materials.9
6 Specimen.10
7 Test conditions and specimen conditioning .11
7.1 Test conditions .11
7.2 Conditioning of specimens .11
8 Calibration.11
8.1 General .11
8.2 Calibration materials .12
8.3 Temperature calibration.12
8.4 Heat calibration.14
8.5 Heat flow rate calibration.15
9 Procedure.17
9.1 Setting up the apparatus .17
9.2 Loading the specimen into the crucible.17
9.3 Insertion of crucibles into the instrument .18
9.4 Performing measurements.18
9.5 Post-run checks.20
10 Test report.21
[11]
Annex A (normative) Extended, high-precision, temperature calibration .22
Annex B (normative) Extended, high-precision, heat calibration.24
Annex C (informative) Recommended calibration materials.26
Annex D (informative) Interaction of calibration materials with different crucible materials .29
Annex E (informative) General recommendations.30
Bibliography.31
© ISO 2009 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11357-1 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This second edition cancels and replaces the first edition (ISO 11357-1:1997), which has been technically
revised. The most important changes are the following:
⎯ an indication has been given of the preferred graphical representation of DSC diagrams in accordance
with thermodynamic requirements;
⎯ an additional, more precise, method of temperature calibration, providing an accuracy of ± 0,3 K over an
extended temperature range, has been included;
⎯ an additional, more precise, procedure for enthalpy calibration, providing an accuracy of ± 0,5 %, has
been included;
⎯ a procedure for heat flow rate calibration has been included;
⎯ information has been included on interactions between calibration materials and the crucibles.
ISO 11357 consists of the following parts, under the general title Plastics — Differential scanning calorimetry
(DSC):
⎯ Part 1: General principles
⎯ Part 2: Determination of glass transition temperature
⎯ Part 3: Determination of temperature and enthalpy of melting and crystallization
⎯ Part 4: Determination of specific heat capacity
⎯ Part 5: Determination of characteristic reaction-curve temperatures and times, enthalpy of reaction and
degree of conversion
⎯ Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature
(dynamic OIT)
⎯ Part 7: Determination of crystallization kinetics
iv © ISO 2009 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
Introduction
ISO 11357 describes thermoanalytical DSC test methods which can be used for quality assurance purposes,
for routine checks of raw materials and finished products or for the determination of comparable data needed
for data sheets or databases. The procedures given in ISO 11357 apply as long as product standards or
standards describing special atmospheres for conditioning of specimens do not specify otherwise.
© ISO 2009 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 11357-1:2010
---------------------- Page: 12 ----------------------
SIST EN ISO 11357-1:2010
INTERNATIONAL STANDARD ISO 11357-1:2009(E)
Plastics — Differential scanning calorimetry (DSC) —
Part 1:
General principles
SAFETY STATEMENT — Persons using this document should be familiar with normal laboratory
practice, if applicable. This document does not purport to address all of the safety concerns, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and health
practices and to ensure compliance with any regulatory requirements.
1 Scope
ISO 11357 specifies several differential scanning calorimetry (DSC) methods for the thermal analysis of
polymers and polymer blends, such as
⎯ thermoplastics (polymers, moulding compounds and other moulding materials, with or without fillers,
fibres or reinforcements);
⎯ thermosets (uncured or cured materials, with or without fillers, fibres or reinforcements);
⎯ elastomers (with or without fillers, fibres or reinforcements).
ISO 11357 is intended for the observation and measurement of various properties of, and phenomena
associated with, the above-mentioned materials, such as
⎯ physical transitions (glass transition, phase transitions such as melting and crystallization, polymorphic
transitions, etc.);
⎯ chemical reactions (polymerization, crosslinking and curing of elastomers and thermosets, etc.);
⎯ the stability to oxidation;
⎯ the heat capacity.
This part of ISO 11357 specifies a number of general aspects of differential scanning calorimetry, such as the
principle and the apparatus, sampling, calibration and general aspects of the procedure and test report
common to all following parts.
Details on performing specific methods are given in subsequent parts of ISO 11357 (see Foreword).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 291, Plastics — Standard atmospheres for conditioning and testing
© ISO 2009 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
ISO 472, Plastics — Vocabulary
ISO 80000-5, Quantities and units — Part 5: Thermodynamics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and ISO 80000-5 and the
following apply.
3.1
differential scanning calorimetry
DSC
technique in which the difference between the rate of flow of heat into a specimen crucible containing the
specimen and that into a reference crucible is derived as a function of temperature and/or time while the
specimen and reference are subjected to the same controlled temperature programme in a specified
atmosphere using a symmetrical measurement system
NOTE 1 It is common practice to record, for each measurement run, a curve in which temperature or time is plotted as
the abscissa and heat flow rate difference as the ordinate. The endothermic and/or exothermic direction is indicated on the
DSC curve.
NOTE 2 According to the principles of thermodynamics, energy absorbed by a system is considered positive while
energy released is negative. This approach implies that the endothermic direction points upwards in the ordinate and the
exothermic direction downwards (see Figures 1 and 2). It also has the advantage that the direction of thermal effects in
plots of heat flow rate and specific heat are consistent.
3.2
calibration material
material for which one or more of the thermal properties are sufficiently homogeneous and well established to
be used for the calibration of a DSC instrument or for the assessment of a measurement method
3.3
reference crucible
crucible used on the reference side of the symmetrical crucible holder assembly
NOTE 1 Normally the reference crucible is empty.
NOTE 2 In special cases, such as the measurement of highly filled or reinforced polymers or specimens having a heat
capacity comparable to that of the crucible, a suitable material can be used inside the reference crucible. This reference
material should be thermally inactive over the temperature and time range of interest and its heat capacity should be
similar to that of the specimen. In the case of filled or reinforced products, the pure filler or reinforcement can be used, for
example.
3.4
heat flow rate
quantity of heat transferred per unit time (dQ/dt), expressed in watts (W) or milliwatts (mW)
NOTE The total quantity of heat transferred, Q, corresponds to the time integral of the heat flow rate:
dQ
Qt= d (1)
∫
dt
2 © ISO 2009 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
3.5
change in heat
∆Q
quantity of heat absorbed (endothermic, ∆Q positive) or released (exothermic, ∆Q negative) within a specified
time, t, or temperature, T, range by a specimen undergoing a chemical or physical change and/or a
temperature change:
t
2
dQ
∆=Qtd (2)
∫
dt
t
1
or
T
2
60 dQ
∆=QTd (3)
∫
β dt
T
1
where
∆Q is expressed in joules (J) or as a specific quantity, ∆q, expressed in joules per amount of material in
−1 −1
grams (J⋅g ) or joules per amount of material in moles (J⋅mol );
−1
β is the constant heating or cooling rate, dT/dt, expressed in kelvins per minute (K⋅min ).
NOTE If measurements are made at constant pressure, ∆Q corresponds to the change in enthalpy, ∆H.
3.6
specific heat capacity at constant pressure
c
p
quantity of heat necessary to raise the temperature of unit mass of material by 1 K at constant pressure:
1d⎛⎞Q
c =× (4)
⎜⎟
p
mTd
⎝⎠
p
or
160⎛⎞dQ
c =× × (5)
p ⎜⎟
mtβ d
⎝⎠
p
where
dQ is the quantity of heat, expressed in joules (J), necessary to raise the temperature of an amount of
material of mass m, expressed in grams (g), by dT kelvins at constant pressure;
−1
β is the heating rate, expressed in kelvins per minute (K⋅min );
−1 −1
c is expressed in joules per gram per kelvin (J⋅g ⋅K )
p
−1 −1
NOTE 1 c may also be expressed in joules per mole per kelvin (J⋅mol ⋅K ) when the amount of material, m, is
p
expressed in moles.
NOTE 2 When analysing polymers, it is necessary to ensure that the measured specific heat capacity does not include
any heat change due to a chemical reaction or a physical transition.
© ISO 2009 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
3.7
baseline
that part of the recorded curve in which no reactions or transitions take place
NOTE 1 This can be an isothermal baseline when the temperature is maintained constant or a dynamic baseline when
the temperature is changed in accordance with a controlled temperature programme.
NOTE 2 The baselines defined in 3.7.1 to 3.7.3 refer to the quasi-stationary range only, i.e. when the instrument is
operating under stable conditions shortly after starting and shortly before ending the DSC run (see Figure 1).
Key
dQ/dt heat flow rate 3 specimen baselines
T temperature 4 virtual baseline
t time 5 instrument baseline
1 dQ/dt vs t (or T) 6 quasi-stationary range
2 T vs t 7 isothermal start baseline
8 isothermal end baseline
a
Endothermic direction.
Figure 1 — Schematic drawing showing baselines
3.7.1
instrument baseline
curve obtained using only empty crucibles of identical mass and material in the specimen and reference
positions of the DSC cell
NOTE The instrument baseline is required for heat capacity measurements.
3.7.2
specimen baseline
DSC curve obtained outside any reaction or transition zone(s) while the instrument is loaded with both the
specimen in the specimen crucible and the reference crucible
NOTE 1 In this part of the curve, the difference in heat flow rate between the specimen crucible and the reference
crucible depends solely on the heat capacity of the specimen and the instrument baseline.
4 © ISO 2009 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
NOTE 2 The specimen baseline reflects the relatively low temperature dependence of the heat capacity of the
specimen and is thus approximately constant, i.e. the baseline is approximately flat.
NOTE 3 For heat capacity determinations, a dynamic DSC curve is required and, in addition, the instrument baseline
and the isothermal start and end baselines (see Figure 1).
3.7.3
virtual baseline
imaginary line drawn through a reaction and/or transition zone assuming the heat of reaction and/or transition
to be zero
NOTE 1 Assuming the change in heat capacity with temperature to be linear, the virtual baseline is drawn by
interpolating or extrapolating the specimen baseline in a straight line. It is normally indicated on the DSC curve for
convenience (see Figures 1 and 2).
NOTE 2 The virtual baseline drawn from peak onset, T , to peak end, T , (the peak baseline) allows the determination of
i f
the peak area from which the heat of transition can be obtained. If there is no significant change in heat capacity during
the transition or reaction, the baseline can be drawn simply by connecting the peak onset and peak end by a straight line.
If significant heat capacity changes occur, a sigmoidal baseline can be drawn.
NOTE 3 Extrapolated and interpolated virtual baselines will not necessarily coincide with each other (see Figure 2).
3.8
step
abrupt positive or negative change in the height of a DSC curve, taking place over a limited temperature range
NOTE A step in the DSC curve can be caused by e.g. a glass transition (see Figure 2).
3.8.1
step height
difference between the heights of the extrapolated baselines before and after a step, measured at the time or
temperature corresponding to the point on the DSC curve which is equidistant between the two baselines
3.9
peak
part of the DSC curve which departs from the specimen baseline, reaches a maximum or minimum, and
subsequently returns to the specimen baseline
NOTE A peak in the DSC curve may indicate a chemical reaction or a first-order transition. The initial departure of the
peak from the virtual baseline corresponds to the start of the reaction or transition.
3.9.1
endothermic peak
peak in which the rate of flow of heat into the specimen crucible is greater than that into the reference crucible
NOTE This corresponds to a transition which absorbs heat.
3.9.2
exothermic peak
peak in which the rate of flow of heat into the specimen crucible is less than that into the reference crucible
NOTE This corresponds to a transition which releases heat.
3.9.3
peak area
area enclosed by a peak and the interpolated virtual baseline
3.9.4
peak height
greatest distance in the ordinate direction between the interpolated virtual baseline and the DSC curve during
a peak
© ISO 2009 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
NOTE The peak height, which is expressed in watts (W) or watts per gram (W/g), is not necessarily proportional to
the mass of the specimen.
3.9.5
peak width
distance between the onset and end temperatures or times of a peak
3.10
characteristic temperatures, T, and times, t
These are defined in Figure 2, which shows a typical DSC curve.
NOTE 1 For all types of DSC instrument, a distinction needs to be made between two different categories of
temperature:
⎯ the temperature at the reference position;
⎯ the temperature at the specimen position.
The reference position temperature is the one which is preferred for plotting thermograms. If the specimen position
temperature is used, then this information will need to be included in the test report.
NOTE 2 Characteristic temperatures are expressed in degrees Celsius (°C), relative temperatures and temperature
differences in kelvins (K) and characteristic times in seconds (s) or minutes (min) (see Figure 2).
NOTE 3 The DSC curve can also be plotted using time, t, as the abscissa instead of temperature, T.
6 © ISO 2009 – All rights reserved
---------------------- Page: 18 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
Key
dQ/dt heat flow rate 1 extrapolated baseline
T temperature (or t, time) 2 interpolated baseline
Characteristic temperatures
The first subscript, or pair of subscripts, denotes the position on the DSC curve with respect to the step or peak:
⎯ onset temperature T first detectable departure of curve from extrapolated start
i
baseline;
⎯ interpolated or extrapolated onset temperature T (for a peak) point of intersection of interpolated virtual
ei
baseline and tangent drawn at point of inflection of near
side of peak or (for a step) point of intersection of
extrapolated start baseline and tangent drawn at point of
inflection of step;
⎯ midpoint temperature T half-height of a step;
1/2
⎯ peak temperature T greatest distance between curve and virtual baseline during
p
a peak;
⎯ interpolated or extrapolated end temperature T (for a peak) point of intersection of interpolated virtual
ef
baseline and tangent drawn at point of inflection of far side
of peak or (for a step) point of intersection of extrapolated
end baseline and tangent drawn at point of inflection of
step;
⎯ end temperature T last detectable deviation of curve from extrapolated end
f
baseline.
The second subscript indicates the type of transition:
g glass transition;
c crystallization;
m melting.
a
Endothermic direction.
Figure 2 — Typical DSC curve (schematic)
© ISO 2009 – All rights reserved 7
---------------------- Page: 19 ----------------------
SIST EN ISO 11357-1:2010
ISO 11357-1:2009(E)
4 Basic principles
4.1 General
The difference between the rate of heat flow into a specimen and that into a reference crucible is measured as
a function of temperature and/or time while the specimen and the reference are subjected to the same
temperature-control programme under a specified atmosphere.
Two types of DSC can be carried out: heat-flux DSC and power-compensation DSC.
4.2 Heat-flux DSC
The specimen and reference positions are subjected to the same temperature-control programme by a single
heater. A difference in temperature, ∆T, occurs between the specimen position and the reference position
because of the difference in heat capacity between the specimen and the reference. From this temperature
difference, the difference in the rates of heat flow i
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.