EN ISO 9771:1997

Plastics - Phenolic resins - Determination of the pseudo-adiabatic temperature rise of liquid resols when cured under acid conditions (ISO 9771:1995)

Cancels and replaces the first edition (1989). Specifies a method for determining the exothermic reactivity of thermosetting liquid phenolic resins when mixed with an acid hardener under specified conditions. The results of the determination are used as a means of assessing the behaviour of the resin during processing.

Kunststoffe - Phenolharze - Bestimmung des pseudo-adiabatischen Temperaturanstiegs flüssiger Resole bei Aushärtung unter sauren Bedingungen (ISO 9771:1995)

Diese Internationale Norm beschreibt ein Verfahren zur Bestimmung der exothermenReaktivität von flüssigen Phenolresolen bei Zusatz eines sauren Härters unterfestgelegten Versuchsbedingungen. Die Ergebnisse der Messungen dienen zur Beurteilung des Verhaltens bei der Verarbeitung.

Plastiques - Résines phénoliques - Détermination de l'élévation de température pseudoadiabatique des résols liquides thermodurcis en conditions acides (ISO 9771:1995)

La présente Norme internationale prescrit une méthode pour la détermination de la réactivité exothermique des résines phénoliques thermodurcissables liquides mélangées à un durcisseur acide dans des conditions spécifiques. Les résultats de l'essai permettent d'estimer le comportement de la résine au durcissement.

Polimerni materiali – Fenolne smole - Določevanje psevdo-adiabatskega porasta temperature tekočih rezolov (ISO 9771:1995)

General Information

• Status: Published
• Publication Date: 18-Feb-1997
• Withdrawal Date: 30-Aug-1997
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: CEN/TC 249 - Plastics
• Drafting Committee: CEN/TC 249/SC 1/WG 13 - Thermosets
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 19-Feb-1997
• Completion Date: 19-Feb-1997
• Ref Project: SIST EN ISO 9771:1999 - Plastics - Phenolic resins - Determination of the pseudo-adiabatic temperature rise of liquid resols when cured under acid conditions (ISO 9771:1995)

Overview

EN ISO 9771:1997 is an international standard published by CEN that specifies a method for determining the pseudo-adiabatic temperature rise of liquid phenolic resol resins when cured under acid conditions. This standard is essential for assessing the exothermic reactivity of thermosetting phenolic resins mixed with acid hardeners, providing valuable data on the resin’s behavior during processing. The method outlined in this standard replaces the first edition from 1989 and ensures consistent and reliable measurements that are critical for quality control and formulation optimization in the plastics industry.

Key Topics

• Scope and Purpose
  EN ISO 9771:1997 outlines a laboratory test to measure the highest temperature reached and the time taken during the curing reaction of phenolic resol resins under acidic conditions. This data helps predict processing performance and manage curing parameters in industrial applications.

• Test Principle
  The test involves mixing a phenolic resin with a specified acid hardener. The reaction is conducted in a thermally insulated environment to approximate pseudo-adiabatic conditions. A thermocouple records the temperature rise caused by the exothermic curing reaction.

• Apparatus and Materials
  Key test equipment includes:

  • A polyethylene-impregnated paper cup reaction vessel
  • A hollow foam block for thermal insulation
  • A suitable acid hardener-e.g., phenol sulfonic acid at technical grade
  • Thermocouples and temperature recording devices
  • Stirring devices and precise measuring equipment

• Test Procedure
  The phenolic resin sample is weighed and conditioned at 23 °C ± 0.2 °C before mixing with the acid hardener. Temperature recording starts immediately upon mixing, with continuous stirring for 35 seconds to ensure homogeneity. The time and peak temperature of the curing exotherm are recorded.

• Expression of Results

  • Maximum temperature rise (°C)
  • Time until maximum temperature is reached (minutes)
    Results must be averaged over at least two tests, with precision targets of ±3% repeatability for temperature and ±5% for timing.

• Test Reporting
  Reports must include:

  • Reference to EN ISO 9771:1997
  • Resin and hardener identification
  • Test conditions including starting and maximum temperatures, time to peak temperature, and mixing time used

Applications

EN ISO 9771:1997 is crucial for industries involved in the production and processing of thermosetting phenolic resins, widely used in:

• Automotive parts
• Electrical insulation components
• Laminates and composites
• Adhesives and coatings

By understanding the thermal behavior of phenolic resins during acid curing, manufacturers can optimize processing parameters, improve product consistency, and prevent defects caused by uncontrolled exothermic reactions.

Related Standards

Professionals using EN ISO 9771:1997 often work alongside or reference related international standards, including:

• ISO 4625 and ISO 4626 – Methods for viscosity and resin content in phenolic resins
• ISO 11357 – Plastics-Differential scanning calorimetry (DSC) methods for curing analysis
• EN ISO 9001 – Quality management systems important for ensuring consistent resin production and testing

Summary

EN ISO 9771:1997 provides a standardized procedure for evaluating the exothermic curing characteristics of phenolic resol resins in acid conditions. This method supports better control over resin formulation and processing, enabling manufacturers to enhance product reliability and efficiency. The standard’s precise test setup and repeatable results make it a critical tool in the plastics and thermosetting materials industries, particularly where phenolic resin performance is key.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-1999
3ROLPHUQLPDWHULDOL±)HQROQHVPROH'RORþHYDQMHSVHYGRDGLDEDWVNHJDSRUDVWD
WHPSHUDWXUHWHNRþLKUH]RORY,62
Plastics - Phenolic resins - Determination of the pseudo-adiabatic temperature rise of
liquid resols when cured under acid conditions (ISO 9771:1995)
Kunststoffe - Phenolharze - Bestimmung des pseudo-adiabatischen Temperaturanstiegs
flüssiger Resole bei Aushärtung unter sauren Bedingungen (ISO 9771:1995)
Plastiques - Résines phénoliques - Détermination de l'élévation de température
pseudoadiabatique des résols liquides thermodurcis en conditions acides (ISO
9771:1995)
Ta slovenski standard je istoveten z: EN ISO 9771:1997
ICS:
83.080.10 Duromeri Thermosetting materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL
IS0
STANDARD 9771
Second edition
1995-05-01
- Phenolic resins -
Plastics
Determination of the pseudo-adiabatic
temperature rise of liquid resols when
cured under acid conditions
- R&sines phbnoliques - D&ermination de I%l6vation de
P/as tiques
tempgrature pseudoadiabatique des r&o/s liquides thermodurcis en
conditions acides
Reference number
IS0 9771 :I 995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 9771 was prepared by Technical Committee
lSO/TC 61, Plastics, Subcommittee SC 12, Thermosetting materids.
This second edition cancels and replaces the first edition
(IS0 9771:1989), of which it constitutes a minor revision.
0 IS0 1995
Al 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 the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
II
INTERNATIONAL STANDARD 0 Iso IS0 9771:1995(E)
- Determination of the
Plastics - Phenolic resins
pseudo-adiabatic temperature rise of liquid resols
when cured under acid conditions
4.2 Hollow foam block, made of phenolic-resin or
1 Scope
polyurethane-resin foam with an apparent density of
30 kg/m3 to 50 kg/m3 and with a cavity to accommo-
This International Standard specifies a method for
date the reaction vessel (4.1).
determining the exothermic reactivity of thermo-
setting liquid phenolic resins when mixed with an acid
The cavity shall be arranged so that the surface of the
hardener under specified conditions. The results of
reaction mixture lies about 30 mm below the top
the determination are used as a means of assessing
edge of the foam blo
...