Plastics - Determination of the viscosity of polymers in dilute solution using capillary viscometers - Part 2: Poly(vinyl chloride) resins (ISO 1628-2:2020)

1.1 This document specifies conditions for the determination of the reduced viscosity (also known
as viscosity number) and K-value of PVC resins. It is applicable to resins in powder form which consist
of homopolymers of the monomer vinyl chloride and copolymers, terpolymers, etc., of vinyl chloride
with one or more other monomers, but where vinyl chloride is the main constituent. The resins may
contain small amounts of unpolymerized substances (e.g. emulsifying or suspending agents, catalyst
residues, etc.) and other substances added during the course of the polymerization. This document
is not applicable, however, to resins having a volatile-matter content in excess of 0,5 % ± 0,1 %, when
determined in accordance with ISO 1269. In addition to this, it is not applicable to resins which are not
entirely soluble in cyclohexanone.
1.2 The reduced viscosity and K-value of a particular resin are related to its molecular mass, but the
relationship varies depending on the concentration and type(s) of other monomer(s) present. Hence,
homopolymers and copolymers having the same reduced viscosity or K-value might not have the same
molecular mass.
1.3 The values determined for reduced viscosity and K-value, for a particular sample of PVC resin, are
influenced differently by the concentration of the solution chosen for the determination. Hence the use
of the procedures described in this document only gives values for reduced viscosity and K-value that are
comparable when the concentrations of the solutions used are identical.
1.4 Limiting viscosity number is not used for PVC resins.
1.5 The experimental procedures described in this document can also be used to characterize the
polymeric fraction obtained during the chemical analysis of a PVC composition. However, the values
calculated for the reduced viscosity and K-value in these circumstances might not indicate the actual
values for the resin used to produce the composition because of the impure nature of the recovered
polymer fraction.

Kunststoffe - Bestimmung der Viskosität von Polymeren in verdünnter Lösung unter Verwendung von Kapillarviskosimetern - Teil 2: Vinylchlorid-Polymere (ISO 1628-2:2020)

1.1 Dieses Dokument legt Bedingungen für die Bestimmung der reduzierten Viskosität (auch bekannt als Viskositätszahl) und des K Wertes von VC Polymeren fest. Es ist anwendbar auf Polymere in pulvriger Form, die aus Homopolymeren des Monomers Vinylchlorid und Co  oder Terpolymeren usw. von Vinylchlorid mit einem oder mehreren anderen Monomeren bestehen, wobei aber Vinylchlorid den Hauptbestandteil darstellt. Die Polymere können kleine Mengen nicht polymerisierter Substanzen (z. B. Emulgatoren oder Suspensionshilfsmittel, Katalysatorreste usw.) sowie anderer Substanzen enthalten, die im Laufe der Polymerisation hinzugegeben werden. Dieses Dokument ist jedoch nicht anwendbar auf Polymere, die einen höheren Anteil als 0,5 % ± 0,1 % an flüchtigen Bestandteilen gemäß der Bestimmung nach ISO 1269 aufweisen. Darüber hinaus ist es nicht anwendbar auf Polymere, die nicht vollständig in Cyclohexanon löslich sind.
1.2 Die reduzierte Viskosität und der K Wert eines bestimmten Polymers sind abhängig von seiner molaren Masse, aber diese Abhängigkeit variiert mit der Konzentration und dem Typ anderer vorhandener Monomere. Deshalb ist es möglich, dass Homo  und Copolymere mit gleicher reduzierter Viskosität oder gleichem K Wert nicht dieselbe molare Masse aufweisen.
1.3 Die für eine bestimmte Probe eines VC Polymers ermittelten Werte für die reduzierte Viskosität und den K Wert werden unterschiedlich von der für die Messung gewählten Konzentration der Lösung beeinflusst. Deshalb ergeben sich durch die Anwendung der in diesem Dokument beschriebenen Verfahren nur dann vergleichbare Werte für die reduzierte Viskosität und den K Wert, wenn die Konzentrationen der verwendeten Lösungen identisch sind.
1.4 Die Grenzviskositätszahl (en: limiting viscosity number) findet für VC Polymere keine Anwendung.
1.5 Die in diesem Dokument beschriebenen Bestimmungsverfahren können auch zur Charakterisierung der im Rahmen einer chemischen Analyse einer PVC Formmasse erhaltenen Polymerfraktion benutzt werden. Die so berechneten Werte für die reduzierte Viskosität und den K Wert könnten in diesem Fall jedoch von dem tatsächlichen Wert für das in der Formmasse enthaltene Polymer abweichen, weil die erhaltene Polymerfraktion im Allgemeinen verunreinigt ist.

Plastiques - Détermination de la viscosité des polymères en solution diluée à l'aide de viscosimètres à capillaires - Partie 2: Résines de poly (chlorure de vinyle) (ISO 1628-2:2020)

1.1 Le présent document spécifie les conditions particulières nécessaires à la détermination de la viscosité réduite (également appelée « indice de viscosité ») et de la valeur K des résines PVC. Il est applicable aux résines sous forme de poudres composées d'homopolymères de chlorure de vinyle monomère et de copolymères, terpolymères, etc., de chlorure de vinyle combiné avec un ou plusieurs autres monomères, le chlorure de vinyle étant cependant le principal constituant. Ces résines peuvent contenir de petites quantités de substances non polymérisées (telles qu'émulsifiants ou agents de suspension, résidus de catalyseurs, etc.) ainsi que d'autres substances ajoutées au cours de la polymérisation. Cependant, le présent document ne s'applique pas aux résines dont la teneur en substances volatiles est supérieure à 0,5 % ± 0,1 %, la détermination ayant été effectuée conformément à l'ISO 1269. Il ne s'applique pas non plus aux résines qui ne sont pas entièrement solubles dans la cyclohexanone.
1.2 La viscosité réduite et la valeur K d'une résine donnée sont liées à la masse moléculaire de cette dernière, mais cette relation varie suivant la concentration et le type de l'autre (des autres) monomère(s) également présent(s). De ce fait, il se peut que des homopolymères et des copolymères ayant la même viscosité réduite ou présentant la même valeur K n'aient pas la même masse moléculaire.
1.3 Les valeurs déterminées de la viscosité réduite et de la valeur K, pour un échantillon particulier de résine PVC, sont influencées différemment par la concentration de la solution choisie pour effectuer les déterminations. Ainsi, l'utilisation de modes opératoires décrits dans le présent document donne des valeurs pour la viscosité réduite et la valeur K qui ne sont comparables que lorsque les concentrations des solutions utilisées sont identiques.
1.4 L'indice limite de viscosité n'est pas utilisé dans le cas des résines PVC.
1.5 Les modes opératoires d'essai décrits dans le présent document peuvent également être utilisés pour caractériser la fraction polymérique obtenue au cours de l'analyse chimique d'une composition PVC. Cependant, il est improbable que les valeurs de la viscosité réduite ou de K obtenues par calcul dans ces conditions indiquent les valeurs réelles qui caractérisent la résine utilisée pour obtenir ladite composition, étant donné le caractère impur de la fraction polymérique récupérée.

Polimerni materiali - Določanje viskoznosti polimerov v razredčenih raztopinah s kapilarnimi viskozimetri - 2. del: Polivinilklorid (ISO 1628-2:2020)

General Information

Status
Published
Public Enquiry End Date
30-Apr-2020
Publication Date
28-Jul-2020
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
23-Jul-2020
Due Date
27-Sep-2020
Completion Date
29-Jul-2020

RELATIONS

Buy Standard

Standard
SIST EN ISO 1628-2:2020
English language
22 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 1628-2:2020
01-oktober-2020
Nadomešča:
SIST EN ISO 1628-2:2000
Polimerni materiali - Določanje viskoznosti polimerov v razredčenih raztopinah s
kapilarnimi viskozimetri - 2. del: Polivinilklorid (ISO 1628-2:2020)

Plastics - Determination of the viscosity of polymers in dilute solution using capillary

viscometers - Part 2: Poly(vinyl chloride) resins (ISO 1628-2:2020)
Kunststoffe - Bestimmung der Viskosität von Polymeren in verdünnter Lösung unter

Verwendung von Kapillarviskosimetern - Teil 2: Vinylchlorid-Polymere (ISO 1628-2:2020)

Plastiques - Détermination de la viscosité des polymères en solution diluée à l'aide de

viscosimètres à capillaires - Partie 2: Résines de poly (chlorure de vinyle) (ISO 1628-

2:2020)
Ta slovenski standard je istoveten z: EN ISO 1628-2:2020
ICS:
83.080.20 Plastomeri Thermoplastic materials
SIST EN ISO 1628-2:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN ISO 1628-2:2020
---------------------- Page: 2 ----------------------
SIST EN ISO 1628-2:2020
EN ISO 1628-2
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2020
EUROPÄISCHE NORM
ICS 83.080.20 Supersedes EN ISO 1628-2:1998
English Version
Plastics - Determination of the viscosity of polymers in
dilute solution using capillary viscometers - Part 2:
Poly(vinyl chloride) resins (ISO 1628-2:2020)

Plastiques - Détermination de la viscosité des Kunststoffe - Bestimmung der Viskosität von

polymères en solution diluée à l'aide de viscosimètres Polymeren in verdünnter Lösung unter Verwendung

à capillaires - Partie 2: Résines de poly(chlorure de von Kapillarviskosimetern - Teil 2: Vinylchlorid-

vinyle) (ISO 1628-2:2020) Polymere (ISO 1628-2:2020)
This European Standard was approved by CEN on 9 June 2020.

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-CENELEC 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-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 1628-2:2020 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 1628-2:2020
EN ISO 1628-2:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

---------------------- Page: 4 ----------------------
SIST EN ISO 1628-2:2020
EN ISO 1628-2:2020 (E)
European foreword

This document (EN ISO 1628-2:2020) 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 January 2021, and conflicting national standards shall

be withdrawn at the latest by January 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 1628-2:1998.

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,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 1628-2:2020 has been approved by CEN as EN ISO 1628-2:2020 without any

modification.
---------------------- Page: 5 ----------------------
SIST EN ISO 1628-2:2020
---------------------- Page: 6 ----------------------
SIST EN ISO 1628-2:2020
INTERNATIONAL ISO
STANDARD 1628-2
Third edition
2020-06
Plastics — Determination of the
viscosity of polymers in dilute solution
using capillary viscometers —
Part 2:
Poly(vinyl chloride) resins
Plastiques — Détermination de la viscosité des polymères en solution
diluée à l'aide de viscosimètres à capillaires —
Partie 2: Résines de poly(chlorure de vinyle)
Reference number
ISO 1628-2:2020(E)
ISO 2020
---------------------- Page: 7 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Principle ........................................................................................................................................................................................................................ 2

5 Materials ....................................................................................................................................................................................................................... 2

6 Apparatus ..................................................................................................................................................................................................................... 2

7 Sampling ........................................................................................................................................................................................................................ 3

8 Number of determinations ........................................................................................................................................................................ 3

9 Procedure..................................................................................................................................................................................................................... 3

9.1 Preparation of solution .................................................................................................................................................................... 3

9.2 Determination of efflux times .................................................................................................................................................... 3

10 Expression of results ........................................................................................................................................................................................ 4

10.1 Reduced viscosity ................................................................................................................................................................................. 4

10.2 K-value............................................................................................................................................................................................................ 4

11 Precision ....................................................................................................................................................................................................................... 5

12 Test report ................................................................................................................................................................................................................... 5

Annex A (informative) Conversion of viscosity ratio (VR) to reduced viscosity (I) and K-value ............6

Bibliography .............................................................................................................................................................................................................................15

© ISO 2020 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9,

Thermoplastic materials, in collaboration with the European Committee for Standardization (CEN)

Technical Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation

between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces ISO 1628-2:1998, of which it constitutes a minor revision.

The change compared to the previous edition is as follows:
— Clause 2 has been updated;
— the former Table 1 has been moved to the new informative Annex A.
A list of all parts in the ISO 1628 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 2020 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 1628-2:2020
INTERNATIONAL STANDARD ISO 1628-2:2020(E)
Plastics — Determination of the viscosity of polymers in
dilute solution using capillary viscometers —
Part 2:
Poly(vinyl chloride) resins
1 Scope

1.1 This document specifies conditions for the determination of the reduced viscosity (also known

as viscosity number) and K-value of PVC resins. It is applicable to resins in powder form which consist

of homopolymers of the monomer vinyl chloride and copolymers, terpolymers, etc., of vinyl chloride

with one or more other monomers, but where vinyl chloride is the main constituent. The resins may

contain small amounts of unpolymerized substances (e.g. emulsifying or suspending agents, catalyst

residues, etc.) and other substances added during the course of the polymerization. This document

is not applicable, however, to resins having a volatile-matter content in excess of 0,5 % ± 0,1 %, when

determined in accordance with ISO 1269. In addition to this, it is not applicable to resins which are not

entirely soluble in cyclohexanone.

1.2 The reduced viscosity and K-value of a particular resin are related to its molecular mass, but the

relationship varies depending on the concentration and type(s) of other monomer(s) present. Hence,

homopolymers and copolymers having the same reduced viscosity or K-value might not have the same

molecular mass.

1.3 The values determined for reduced viscosity and K-value, for a particular sample of PVC resin, are

influenced differently by the concentration of the solution chosen for the determination. Hence the use

of the procedures described in this document only gives values for reduced viscosity and K-value that are

comparable when the concentrations of the solutions used are identical.
1.4 Limiting viscosity number is not used for PVC resins.

1.5 The experimental procedures described in this document can also be used to characterize the

polymeric fraction obtained during the chemical analysis of a PVC composition. However, the values

calculated for the reduced viscosity and K-value in these circumstances might not indicate the actual

values for the resin used to produce the composition because of the impure nature of the recovered

polymer fraction.
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 1042, Laboratory glassware — One-mark volumetric flasks

ISO 1628-1:2009, Plastics — Determination of the viscosity of polymers in dilute solution using capillary

viscometers — Part 1: General principles

ISO 3105:1994, Glass capillary kinematic viscometers — Specifications and operating instructions

© ISO 2020 – All rights reserved 1
---------------------- Page: 11 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1628-1 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 Principle

4.1 A test portion is dissolved in a solvent. The reduced viscosity and the K-value are calculated from

the efflux times for the solvent and the solution in a capillary tube viscometer.

5 Materials
−6 2 –1

5.1 Cyclohexanone, having a viscosity/density ratio (kinematic viscosity) between 2,06 × 10 m s

−6 2 –1 2 –1 2 –1

and 2,33 × 10 m s (2,06 mm s and 2,33 mm s ) at 25 °C. The specified boiling point shall be

155 °C. Store the solvent in the dark in a dark-coloured bottle fitted with a ground-glass stopper. Check

the kinematic viscosity before use.
6 Apparatus

6.1 The apparatus required to carry out viscosity measurements on polymers in dilute solution are in

accordance with ISO 1628-1:2009, Clause 5. In addition, the following particular items are required for

the procedures described in this document.

6.2 Viscometer. From the viscometers described in ISO 1628-1:2009, 5.1, model 1C, with a capillary

diameter of 0,77 (1 ± 2 %) mm, from ISO 3105:1994, Table B.4, shall be used as the reference viscometer.

Other viscometers described in ISO 1628-1 may be used provided the correlation between the chosen

viscometer and the reference viscometer has been established over the range of reduced viscosities and

K-values to be measured, and the results are corrected accordingly.

6.3 Graduated flask (one-mark volumetric flask), class A, as specified in ISO 1042, with a volume

of 50 ml.

NOTE The use of a flask calibrated at a temperature of 20 °C, as specified in ISO 1042, causes a systematic

error which can, however, be neglected.

6.4 Filter funnel, with fritted-glass filter disc of medium porosity (pore size 40 µm to 50 µm), or glass

funnel with paper filter.

6.5 Mechanical agitator, equipped with a heating device to keep the flask (6.3) and its contents at a

temperature between 80 °C and 85 °C.

As an alternative, a rotary agitator or shaker may be placed in an oven at a temperature between 80 °C

and 85 °C.
6.6 Analytical balance, accurate to 0,1 mg.

6.7 Temperature-regulated bath, capable of being set at 25,0 °C ± 0,5 °C in steps of 0,1 °C and

maintaining a stability of ± 0,05 °C around the set temperature.
2 © ISO 2020 – All rights reserved
---------------------- Page: 12 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
6.8 Thermometer, with a sensitivity of 0,05 °C.
6.9 Time-measuring device, with a sensitivity of 0,1 s.
7 Sampling

Take a sample which is representative of the resin whose properties are to be determined and large

enough for at least two determinations.
8 Number of determinations
Carry out two complete determinations, starting each with a fresh test portion.
9 Procedure
9.1 Preparation of solution

General requirements for the dissolution of polymer in solvent are given in ISO 1628-1:2009, Clause 6.

3 3

Prepare a solution with a concentration of 5 kg/m ± 0,1 kg/ m at 25 °C ± 1 °C, as follows.

Weigh, to the nearest 0,2 mg, 0,250 g ± 0,005 g of resin and transfer it quantitatively to the 50 ml

flask (6.3). Add about 40 ml of cyclohexanone (5.1) to the flask, swirling the flask by hand to prevent

coagulation or the formation of lumps. Continue dissolution by agitating for 1 h between 80 °C and

85 °C using the agitator (6.5). Check visually that dissolution is complete. If gelatinized particles are

still visible, start again with a new portion of the resin. Cool the solution to 25 °C ± 1 °C and make up to

the mark with cyclohexanone at the same temperature. Mix the solution thoroughly by shaking.

Determine the actual concentration of the solution to an accuracy of ± 0,1 %.

If a mass of 0,250 g ± 0,000 25 g is taken and made up to 50 ml of solution as described above, Table A.1

in Annex A can be used to read off the reduced viscosity and K-value from the ratio of the efflux time of

the solution to that of the solvent (the so-called viscosity ratio).

Alternative methods for the preparation of the solution may be used, for example the addition of a

measured volume of solvent to a measured mass of test portion, provided that the values obtained for

the reduced viscosity and K-value can be shown to be equivalent to those obtained with the method

of solution preparation described above. Such alternative methods of solution preparation requires

the amounts of solvent and test portion taken to be determined by experiment, and can also require

compensation for loss of solvent by evaporation during the dissolution process.

With resins having K-values greater than 85, the ratio of the efflux time of the solution to that of

the solvent will exceed the maximum value of 2,0, which is contrary to the requirement specified in

ISO 1628-1:2009, 6.2. In order to ensure uniformity of testing for PVC, this non-conformity shall be

ignored, and all currently available resins tested using the same test-portion mass.

9.2 Determination of efflux times
The procedure is described in ISO 1628-1:2009, Clause 8.

The temperature of the thermostat (6.7) shall be set such that the actual temperature which is measured

by the thermometer (6.8) lies in the range 25 °C ± 0,5 °C. The measured temperature shall be stable to

±0,05 °C around the temperature at which the thermostat has been set.

When filling the viscometer, filter the solvent and the solution using a filter funnel or a glass funnel and

paper filter (see 6.4).
© ISO 2020 – All rights reserved 3
---------------------- Page: 13 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)

Particular care shall be taken over viscometer cleaning, which shall be based on the procedure described

in ISO 1628-1:2009, Annex A. Efflux times with the control solvent cyclohexanone shall remain constant

to within 0,2 s for a given viscometer. With the solution, repeat the measurement of the efflux time until

two successive measurements differ by less than 0,25 %. Always discard the first efflux time reading.

NOTE This is a manual procedure. Proprietary equipment is available which will organize the charging of

the viscometer with solution and solvent and measure the respective efflux times automatically. The use of such

equipment is included in the scope of this document provided that all the procedures and verification checks

described above are followed by the automated procedure.
10 Expression of results
10.1 Reduced viscosity

Calculate the reduced viscosity, I, for each test portion as specified in ISO 1628-1:2009, Clause 9, using

Formula (1):
tt−
I= (1)
where

t and t are the efflux times, in seconds, of the solution and solvent, respectively;

3 3 3
c is the concentration of the solution, in 10 kg/m , i.e. g/cm .

Calculate the reduced viscosity I for the sample as the mean value of the two individual values obtained

in the two determinations, expressing the result to the nearest whole number. If the I values obtained

in the two determinations deviate by more than ± 0,4 % from the mean value, these results shall be

rejected and further determinations carried out with fresh test portions.
3 3

If the solution concentration is 5 kg/m ± 0,005 kg/m , it is more convenient to read off the values of I

3 −3 3

from Table A.1, expressing I in (m /kg) · 10 , i.e. cm /g, rounded to the first place of decimals.

10.2 K-value

For each test portion, calculate the K-value as specified in ISO 1628-1:2009, Clause 9, using Formula (2):

 
15,lg,ηη−+11++21+ 51lg ,l5 gη
 
rr r
 
K = ×1000 (2)
150+300c
where
η t
is the ratio of the viscosities (efflux times) of the solution and solvent;
η ==
η t

t and t are the efflux times, in seconds, of the solution and solvent, respectively;

3 3 3
c is the concentration of the solution, in 10 kg/m , i.e. g/cm .

Calculate the K-value for the sample as the mean value of the two individual K-values obtained in the

two determinations, expressing the result to the first place of decimals. If the K-values obtained in the

two determinations deviate by more than ± 0,4 % from the mean value, these results shall be rejected

and further determinations carried out with fresh test portions.
3 3

If the solution concentration is 5 kg/m ± 0,005 kg/m , it is more convenient to read off the K-value

from Table A.1, rounding to the second place of decimals.
4 © ISO 2020 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
11 Precision

Interlaboratory trials were conducted on three resins in 11 laboratories on four different dates. These

interlaboratory trials gave the following results for the repeatability standard deviation s (within the

same laboratory) and the reproducibility standard deviation s (among different laboratories).

See Table 1.
Table 1 — Results for s , s of K-value and reduced viscosity
r R
K-value Reduced viscosity

Approximately Approximately Approximately Approximately Approximately Approximately

50 70 90 61 124 227
s 0,132 0,115 0,120 0,313 0,458 0,742
s 0,420 0,291 0,495 0,984 1,202 3,042
12 Test report
The test report shall include the following information:
a) a reference to this document, i.e. ISO 1628-2:2020;
b) all details necessary for complete identification of the material under test;
c) the reduced viscosity and/or K-value of the resin sample;

d) any difference between the type of viscometer used and the reference viscometer specified in this

document;
e) the date of the test.
© ISO 2020 – All rights reserved 5
---------------------- Page: 15 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
Annex A
(informative)
Conversion of viscosity ratio (VR) to reduced viscosity (I) and
K-value
See Table A.1.

Table A.1 — Conversion of viscosity ratio (VR) to reduced viscosity (I) and K-value

3 −3 3
Unit for reduced viscosity: (m /kg) × 10 , i.e. cm /g
Concentration of resin in solution = 5 g/cm
VR I K VR I K VR I K
1,195 39,0 39,74 1,237 47,4 44,02 1,279 55,8 47,87
1,196 39,2 39,85 1,238 47,6 44,12 1,280 56,0 47,95
1,197 39,4 39,95 1,239 47,8 44,22 1,281 56,2 48,04
1,198 39,6 40,06 1,240 48,0 44,31 1,282 56,4 48,13
1,199 39,8 40,17 1,241 48,2 44,41 1,283 56,6 48,21
1,200 40,0 40,27 1,242 48,4 44,50 1,284 56,8 48,30
1,201 40,2 40,38 1,243 48,6 44,60 1,285 57,0 48,38
1,202 40,4 40,49 1,244 48,8 44,69 1,286 57,2 48,47
1,203 40,6 40,59 1,245 49,0 44,79 1,287 57,4 48,55
1,204 40,8 40,70 1,246 49,2 44,88 1,288 57,6 48,64
1,205 41,0 40,80 1,247 49,4 44,98 1,289 57,8 48,72
1,206 41,2 40,91 1,248 49,6 45,07 1,290 58,0 48,81
1,207 41,4 41,01 1,249 49,8 45,16 1,291 58,2 48,89
1,208 41,6 41,12 1,250 50,0 45,26 1,292 58,4 48,98
1,209 41,8 41,22 1,251 50,2 45,35 1,293 58,6 49,06
1,210 42,0 41,33 1,252 50,4 45,44 1,294 58,8 49,15
1,211 42,2 41,43 1,253 50,6 45,53 1,295 59,0 49,23
1,212 42,4 41,53 1,254 50,8 45,63 1,296 59,2 49,32
1,213 42,6 41,64 1,255 51,0 45,72 1,297 59,4 49,40
1,214 42,8 41,74 1,256 51,2 45,81 1,298 59,6 49,48
1,215 43,0 41,84 1,257 51,4 45,90 1,299 59,8 49,57
1,216 43,2 41,94 1,258 51,6 45,99 1,300 60,0 49,65
1,217 43,4 42,05 1,259 51,8 46,09 1,301 60,2 49,73
1,218 43,6 42,15 1,260 52,0 46,18 1,302 60,4 49,81
1,219 43,8 42,25 1,261 52,2 46,27 1,303 60,6 49,90
1,220 44,0 42,35 1,262 52,4 46,36 1,304 60,8 49,98
1,221 44,2 42,45 1,263 52,6 46,45 1,305 61,0 50,06
1,222 44,4 42,55 1,264 52,8 46,54 1,306 61,2 50,14
1,223 44,6 42,65 1,265 53,0 46,63 1,307 61,4 50,23
1,224 44,8 42,75 1,266 53,2 46,72 1,308 61,6 50,31
1,225 45,0 42,85 1,267 53,4 46,81 1,309 61,8 50,39
1,226 45,2 42,95 1,268 53,6 46,90 1,310 62,0 50,47
1,227 45,4 43,05 1,269 53,8 46,99 1,311 62,2 50,55
1,228 45,6 43,15 1,270 54,0 47,07 1,312 62,4 50,63
1,229 45,8 43,25 1,271 54,2 47,16 1,313 62,6 50,71
1,230 46,0 43,34 1,272 54,4 47,25 1,314 62,8 50,79
1,231 46,2 43,44 1,273 54,6 47,34 1,315 63,0 50,87
1,232 46,4 43,54 1,274 54,8 47,43 1,316 63,2 50,95
1,233 46,6 43,64 1,275 55,0 47,52 1,317 63,4 51,03
1,234 46,8 43,73 1,276 55,2 47,60 1,318 63,6 51,11
1,235 47,0 43,83 1,277 55,4 47,69 1,319 63,8 51,19
1,236 47,2 43,93 1,278 55,6 47,78 1,320 64,0 51,27
6 © ISO 2020 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 1628-2:2020
ISO 1628-2:2020(E)
Table A.1 (continued)
VR I K VR I K VR I K
1,321 64,2 51,35 1,371 74,2 55,14 1,421 84,2 58,59
1,322 64,4 51,43 1,372 74,4 55,21 1,422 84,4 58,65
1,323 34,6 51,51 1,373 74,6 55,28 1,423 84,6 58,72
1,324 34,8 51,59 1,374 74,8 55,35 1,424 84,8 58,79
1,325 65,0 51,67 1,375 75,0 55,42 1,425 85,0 58,85
1,326 65,2 51,75 1,376 75,2 55,49 1,426 85,2 58,92
1,327 65,4 51,83 1,377 75,4 55,57 1,427 85,4 58,98
1,328 65,6 51,91 1,378 75,6 55,64 1,428 85,6 59,05
1,329 65,8 51,98 1,379 75,8 55,71 1,429 85,8 59,11
1,330 66,0 52,06 1,380 76,0 55,78 1,430 86,0 59,18
1,331 66,2 52,14 1,381 76,2 55,85 1,431 86,2 59,24
1,332 66,4 52,22 1,382 76,4 55,92 1,432 86,4 59,31
1,333 66,6 52,29 1,383 76,6 55,99 1,433 86,6 59,37
1,334 66,8 52,37 1,384 76,8 56,06 1,434 86,8 59,44
1,335 67,0 52,45 1,385 77,0 56,13 1,435 87,0 59,50
1,336 67,2 52,5
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.