ISO 19935-1:2018

Plastics — Temperature modulated DSC — Part 1: General principles

This document establishes general principles of temperature modulated differential scanning calorimetry (DSC) such as description of the principle and the apparatus, sampling, calibration and general aspects of the procedure and test report common to all parts of the ISO 19335 series. NOTE Details on performing specific methods are intended to be given in the future parts of the ISO 19335 series.

Plastiques — DSC à température modulée — Partie 1: Principes généraux

General Information

• Status: Published
• Publication Date: 24-Sep-2018
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5/WG 8 - Thermal analysis

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 19935-1
First edition
2018-09
Plastics — Temperature modulated
DSC —
Part 1:
General principles
Plastiques — DSC à température modulée —
Partie 1: Principes généraux
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Calculation of heat flow rate and heat capacity . 1
4.1 Temperature modulation, T(t).1
4.2 Heating rate . 2
4.3 Heat flow rate Φ(t) and heat capacity . 2
4.3.1 General. 2
4.3.2 Heat capacity with no processes . 3
4.3.3 Heat capacity with additional processes. 4
4.3.4 Time dependent heat capacity . 5
5 Principles . 5
5.1 General . 5
5.2 Mode of temperature modulation . 5
5.2.1 Variable heating rate of periodic modulation . 5
5.2.2 Variable temperature modulated mode . 6
5.3 Heat capacity determined with the temperature modulation — Complex heat capacity . 7
5.4 Reversing and non-reversing heat capacity . 8
5.5 Advantage of the temperature modulation applied to DSC . 8
6 Apparatus and materials.11
6.1 General .11
6.2 Temperature control of modulated differential scanning calorimeter .11
7 Calibration .12
7.1 General .12
7.2 Calibration of modulation amplitude .12
7.3 Calibration of phase .12
8 Procedure.12
8.1 General .12
8.2 Experimental conditions .13
8.3 Interpretation of results .13
9 Test report .13
[7]
Annex A (informative) Generalized theory of temperature modulated DSC .14
Bibliography .16
Foreword
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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
A list of all parts in the ISO 19935 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2018 – All rights reserved

Introduction
The ISO 19935 series specifies temperature modulated differential scanning calorimetry (DSC)
methods for the thermal analysis of polymers such as thermoplastics, thermosets and elastomers.
It is designed for observing and quantifying various phenomena or properties of the abovementioned
materials such as
— physical transitions (glass transition, phase transitions like melting, crystallization, and cold
crystallization, etc.);
— chemical reactions (cross-linking and curing of elastomers and thermosets, etc.);
— heat capacity;
— separation of overlapping thermal transitions.
This document describes the realization of several standardized thermoanalytical test methods which
can be used for the determination of comparable data needed for data sheets or databases as well as for
research purposes, but it can also be applied to quality assurance or to routine checks of raw materials
and finished products, if desired. The procedures mentioned in this document apply as long as special
product standards or standards describing special atmospheres for conditioning of samples do not
require alternate provisions.
For scientific investigations or resolution of special analytical problems, all technical capabilities of the
instruments beyond the provisions of this document may be used.
INTERNATIONAL STANDARD ISO 19935-1:2018(E)
Plastics — Temperature modulated DSC —
Part 1:
General principles
1 Scope
This document establishes general principles of temperature modulated differential scanning
calorimetry (DSC) such as description of the principle and the apparatus, sampling, calibration and
general aspects of the procedure and test report common to all parts of the ISO 19335 series.
NOTE Details on performing specific methods are intended to be given in the future parts of the
ISO 19335 series.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 472, Plastics — Vocabulary
ISO 11357-1, Plastics — Differential scanning calorimetry (DSC) — Part 1: General principles
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, ISO 11357-1 and
ISO 80000-5 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Calculation of heat flow rate and heat capacity
4.1 Temperature modulation, T(t)
A periodic temperature profile superimposed to a linear temperature change or constant temperature,
is given by Formula (1):
Tt =+Ttβ ⋅+Tf⋅ t (1)
() ()
00 A
where
t is the time;
T is a start temperature;
β is the underlying heating or cooling rate;
T is the amplitude of sample temperature profile;
A
f(t) is the periodic function of the temperature profile.
The periodic temperature profile can have any waveform. Multi-frequency temperature modulation
can be used in one and the same measurement.
4.2 Heating rate
The heating rate is not constant as in the case of conventional differential scanning calorimetry (DSC),
which follows from Formula (1):
dT t df t
() ()
=+β T ⋅ (2)
0A
dt dt
If the temperature profile is a sinusoidal function with angular frequency, ω [see Formula (3)]:
ft = sintω (3)
() ()
Formula (2) is derived as shown in Formula (4):
dT t
()
=+βωTt⋅ ⋅cos ω (4)
()
0A
dt
4.3 Heat flow rate Φ(t) and heat capacity
4.3.1 General
For a temperature perturbation that consists of an underlying part Φ , a periodic part Φ ,
underlying periodic
and an additional endothermic or exothermic excess heat exchange part Φ , the heat flow rate Φ(T, t)
ex.
can be expressed as Formula (5):
ΦΦTt, =+ΦΦ+ (5)
()
underlying periodic ex.
assuming the pure thermodynamic heat capacity is as shown in Formula (6):
dT t
()
ΦΦTt, =CT ⋅ + (6)
() ()
pex.
dt
df t
T ()
A
=+CCβ ⋅ ⋅ +Φ
pp0 ex.
K ω dt
()
2 © ISO 2018 – All rights reserved

where
C is the heat capacity;
p
K(ω) is the frequency-dependent calibration function of the heat capacity (see 7.1).
The different cases are distinguished in 4.3.2 to 4.3.4.
Formulae (5) and (6) are enabled
...