SIST EN 15168:2007

Surface active agents - Determination of hydroxyl value - p-Toluensulfonyl isocyanate (TSI) method and potentiometric titration with tetrabutylammonium hydroxide

This European Standard specifies a method for the determination of hydroxyl value of aliphatic and cyclic hydroxyl compounds with hydroxyl groups attached to primary and secondary carbon atoms.
This European Standard is applicable to polyacetals, temperature sensitive materials, high solids polymer polyols and rigid polyols and phenols.
This European Standard is not suitable for determination of hydroxyl groups attached to tertiary carbon atoms.
NOTE   This method is currently recommended for neutral refined products. However for products that contain an excess of acidic species a validation should be carried out to show that the acidic species either does not interfere or that the acidic species interference has been obviated.

Grenzflächenaktive Stoffe - Bestimmung der Hydroxylzahl - p-Toluolsulfonylisocyanat-(TSI-) Verfahren und potentiometrische Titration mit Tetrabutylammoniumhydroxid

Dieses Dokument legt ein Verfahren zur Bestimmung der Hydroxylzahl von aliphatischen und zyklischen Hydroxylverbindungen fest, deren Hydroxylgruppen an primäre und sekundäre Kohlenstoffatome gebunden sind.
Dieses Dokument gilt für Polyacetale, temperaturempfindliche Substanzen, hochpolymere Polyole, feste Polyole und Phenole.
Dieses Dokument ist nicht zur Bestimmung von an tertiäre Kohlenstoffatome gebundenen Hydroxylgruppen geeignet.
ANMERKUNG   Gegenwärtig wird dieses Verfahren für neutral raffinierte Produkte empfohlen. Bei Produkten jedoch, die einen Überschuss an sauren Bestandteilen enthalten, sollte eine Überprüfung erfolgen, um den Nachweis zu erbringen, dass die sauren Bestandteile nicht stören oder dass die durch die sauren Bestandteile bewirkte Beeinträchtigung beseitigt wurde.

Agents de surface - Détermination de l'indice d'hydroxyle - Méthode au p-toluenesulfonylisocyanate (TSI) et dosage potentiometrique avec l'hydroxyde de tétrabutylammonium

Le présent document spécifie une méthode de détermination de l’indice d’hydroxyle des composés hydroxylés cycliques et aliphatiques dont les groupes hydroxyles sont liés aux atomes de carbone primaires ou secondaires.
Ce document s’applique aux polyacétals, aux matériaux sensibles à la température, aux hauts polymères solides de polyol et aux phénols et polyols rigides.
Ce document ne s’applique pas à la détermination des groupes hydroxyles liées aux atomes de carbone tertiaires.
NOTE   Cette méthode est actuellement recommandée pour les produits neutres et purifiés. Une validation est cependant nécessaire pour les produits contenant un excès d’espèces acides afin de montrer que ces dernières n’interfèrent pas ou que cette interférence a été prise en compte.

Površinsko aktivne snovi - Določevanje hidroksilne vrednosti - Metoda s p-toluen sulfonil izocianatom (metoda s TSI) in potenciometrijsko titracijo s tetrabutilamonijevim hidroksidom

General Information

• Status: Published
• Publication Date: 31-Mar-2007
• Withdrawal Date: 31-Mar-2007
• ICS: 71.100.40 - Surface active agents
• Technical Committee: KDS - Cosmetics, chemical disinfectants and surface active agents
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2007
• Due Date: 01-Apr-2007
• Completion Date: 01-Apr-2007
• Ref Project: EN 15168:2006 - Surface active agents - Determination of hydroxyl value - p-Toluensulfonyl isocyanate (TSI) method and potentiometric titration with tetrabutylammonium hydroxide

Overview

EN 15168:2006 is a CEN standard for the determination of hydroxyl value (OHV) of aliphatic and cyclic hydroxyl compounds using the p-toluenesulfonyl isocyanate (TSI) method followed by potentiometric titration with tetrabutylammonium hydroxide (TBAH) in a non‑aqueous medium. The method quantifies milligrams of KOH equivalent per gram of sample and is intended for many surfactant and polyol matrices, including temperature‑sensitive materials and high‑solids polymer polyols.

Key topics and requirements

• Scope and limitations
  • Applicable to hydroxyl groups attached to primary and secondary carbon atoms.
  • Not suitable for hydroxyl groups on tertiary carbons.
  • Recommended for neutral refined products; samples with excess acidic/basic species require validation to confirm no interference.
• Analytical principle
  • Sample reacts with excess TSI to form an acidic carbamate; residual isocyanate is hydrolyzed, then the acidic carbamate is titrated potentiometrically with TBAH.
• Sample preparation
  • Follow ISO 607 for sampling and division; heat solid samples only to the minimum temperature required to melt and homogenize.
• Reagents and safety
  • Key reagents: TSI, acetonitrile, THF, toluene, and TBAH standard solution.
  • Warning: several reagents (acetonitrile, TSI, TBAH) are hazardous-work in a fume hood and follow laboratory safety procedures.
• Apparatus and measurement
  • Use an automatic potentiometer with dynamic dosing and suitable electrodes for non‑aqueous titration (combined glass electrode or separate pH/reference electrodes with appropriate electrolytes).
• Calculations, precision and reporting
  • OHV calculated from the volume difference between titration end points; results expressed with defined decimal precision.
  • The standard defines repeatability and reproducibility concepts and requires duplicate determinations and full reporting of deviations.

Applications - who uses this standard

• Quality control and R&D laboratories in:
  • Surfactant and detergent manufacturing
  • Polyol and polyurethane supply chains (rigid and high‑solids polyols)
  • Polymer chemistry and specialty chemicals producers handling polyacetals or temperature‑sensitive materials
• Analytical service labs offering OHV testing for raw materials, in‑process samples and finished products where accurate hydroxyl quantification is required for formulation and stoichiometry.

Related standards

• EN ISO 3696 - Water for analytical laboratory use (used for reagent water quality).
• ISO 607 - Sample division for surface active agents.
• EN 13926 - Alternate methods referenced for products with interfering acidic/basic species (validation guidance).

Keywords: EN 15168:2006, hydroxyl value, TSI method, p-toluenesulfonyl isocyanate, potentiometric titration, tetrabutylammonium hydroxide, surface active agents, polyols, non‑aqueous titration, CEN.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Surface active agents - Determination of hydroxyl value - p-Toluensulfonyl isocyanate (TSI) method and potentiometric titration with tetrabutylammonium hydroxideAgents de surface - Détermination de l'indice d'hydroxyle - Méthode au p-toluenesulfonylisocyanate (TSI) et dosage potentiometrique avec l'hydroxyde de tétrabutylammoniumGrenzflächenaktive Stoffe - Bestimmung der Hydroxylzahl - p-Toluolsulfonylisocyanat-(TSI-) Verfahren und potentiometrische Titration mit TetrabutylammoniumhydroxidTa slovenski standard je istoveten z:EN 15168:2006SIST EN 15168:2007en71.100.40Površinsko aktivna sredstvaSurface active agentsICS:SLOVENSKI
STANDARDSIST EN 15168:200701-april-2007

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15168November 2006ICS 71.100.40 English VersionSurface active agents - Determination of hydroxyl value - p-Toluensulfonyl isocyanate (TSI) method and potentiometrictitration with tetrabutylammonium hydroxideAgents de surface - Détermination de l'indice d'hydroxyle -Méthode à la p-toluènesulfonylisocyanate (TSI) et titragepotentiomètrique avec l'hydroxyde de tétrabutylammoniumGrenzflächenaktive Stoffe - Bestimmung der Hydroxylzahl -p-Toluolsulfonylisocyanat-(TSI-) Verfahren undpotentiometrische Titration mitTetrabutylammoniumhydroxidThis European Standard was approved by CEN on 6 October 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, 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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2006 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15168:2006: E

Page Foreword.3 1 Scope.4 2 Normative references.4 3 Terms and definitions.4 4 Principle.4 5 Reagents.5 6 Apparatus.5 7 Sampling.6 8 Procedure.6 9 Calculation and expression of results.8 10 Precision.8 11 Test report.8 Annex A (informative)
Interferences.9 Annex B (informative)
Titration apparatus settings.10 Annex C (informative)
Example for a typical potentiometric titration curve.11 Annex D (informative)
Statistical and other data derived from the results of inter-laboratory tests.12 Bibliography.13

SO2-NCO + R-OH → CH3
SO2-NHCOOR b) hydrolysis of the excess of isocyanate; CH3
SO2-NCO + H2O → CH3
SO2 NH2 + CO2
SO2-NH COOR + OH- → CH3
SO2-N- - COOR + H2O 5 Reagents During the analysis, unless otherwise specified, use only reagents of recognized analytical grade that have been checked in advance as to not interfere with the analytical results. WARNING — Acetonitrile, p-toluenesulfonyl isocyanate and tetrabutylammonium hydroxide being hazardous chemicals: conduct all the operations under a well-ventilated fume hood. 5.1 Water complying with grade 3 as defined in EN ISO 3696. 5.2 Acetonitrile, with water content < 0,01 % (m/m) (CAS number : 75-05-8). 5.3 Toluene, minimum purity 99 % (m/m) (CAS number : 108-88-3). 5.4 Tetrahydrofurane (THF), minimum purity 99 % (m/m) (CAS number : 109-99-9). 5.5 p-Toluenesulfonyl isocyanate (TSI), minimum purity 96 % (m/m) (CAS number : 4083-64-1). Maintain a nitrogen pad above this reagent after opening the flask. 5.6 p-Toluenesulfonyl isocyanate (TSI) reagent solution. Pipette 20 ml of TSI (5.5) into a dry 500 ml volumetric flask half filled with acetonitrile. Make up to the mark with acetonitrile and mix well. This reagent shall be prepared fresh monthly. 5.7 Potassium hydrogen phthalate, primary standard minimum purity 99 %(m/m) dried 2 h at 120 °C (CAS number : 877-24-7). 5.8 Tetra-n-butyl ammonium hydroxide standard volumetric solution, c([CH3 (CH2) 3] 4NOH) = 0,1 mol/l (CAS number : 2052-49-5). in 2-propanol/methanol. 5.9 Electrolyte: 0,4
mol/l tetraethyl ammonium bromide solution (CAS number : 71-91-0) in ethylene glycol (CAS number:107-21-1). 5.10 Electrolyte: saturated LiCl solution (CAS number : 7447-41-8) in ethanol (CAS number : 64-17-5). 6 Apparatus Normal laboratory apparatus, and the following. 6.1 Automatic potentiometer, with drift-controlled data acquisition and dynamic titrimetric dosing equipped with an automatic burette assembly and a magnetic stirrer. 6.2 Electrodes: There are two options for the electrodes definition. 6.2.1 Two electrodes system 6.2.1.1 Glass pH electrode. 6.2.1.2 Ag/AgCl double-junction ground joint diaphragm reference electrode, inner and outer chambers filled with 0,4 mol/l
solution of tetraethyl ammonium bromide in ethylene glycol (5.9). or
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