ISO 24698-2:2018 PDF

Name: ISO 24698-2:2018 — Rubber, raw — Determination of bound acrylonitrile content in acrylonitrile-butadiene rubber (NBR) — Part 2: Kjeldahl method
SKU: ISO 24698-2:2018
Price: 25 EUR
Availability: InStock

Rubber, raw — Determination of bound acrylonitrile content in acrylonitrile-butadiene rubber (NBR) — Part 2: Kjeldahl method

Название (английский):

ISO 24698-2:2018

Rubber, raw — Determination of bound acrylonitrile content in acrylonitrile-butadiene rubber (NBR) — Part 2: Kjeldahl method

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 11
Дата публикации:: 3 октября 2018 г.
Издание:: ISO IS 24698 edition 2 version 1
ICS:: 83.040.10

Тип поставки:

Full version165 €Read online 24h10 €Read online 72h15 €

Язык документа:

ruen

Срок поставки:2 раб. дн. (перевод)

Цена:165 €

Описание (английский):

This document specifies a method for the determination of the bound acrylonitrile content in NBR by an automatic analyser which uses the Kjeldahl method. The method is also applicable to XNBR (carboxylic acrylonitrile-butadiene rubber) and NBIR (acrylonitrile- butadiene-isoprene rubber) as well as NBR latex. NOTE This document and ISO 24698‑1 can give different results on the same rubber sample.

Abstract

Похожие стандарты

Стандарты, упомянутые в описании

Overview

ISO 24698-2:2018 specifies a laboratory method for determining the bound acrylonitrile content in acrylonitrile‑butadiene rubber (NBR) using the Kjeldahl method with an automatic analyser. The standard also applies to XNBR (carboxylic NBR), NBIR (acrylonitrile‑butadiene‑isoprene rubber) and NBR latex. Note that ISO 24698‑2 and ISO 24698‑1 can produce different results on the same sample.

Keywords: ISO 24698-2:2018, acrylonitrile-butadiene rubber, NBR, Kjeldahl method, bound acrylonitrile content, automatic analyser.

Key topics and technical requirements

Principle: Convert nitrogen in the rubber sample to ammonium salt by acid digestion (K2SO4, H2SO4, CuSO4 catalyst), release ammonia with strong alkali, steam‑distill into boric acid and titrate the distillate.

Apparatus: Use an automatic analyser with digestion, distillation and titration units plus a microprocessor to convert titration results to % nitrogen.

Reagents: Typical reagents include sulfuric acid, hydrochloric acid (standard volumetric solutions 0.05 mol·dm−3), sodium hydroxide (10 mol·dm−3), K2SO4, CuSO4·5H2O, boric acid and ethanolic indicators.

Sample preparation:

Raw NBR/XNBR/NBIR: sampling and milling per ISO 1795, solvent extraction (ethanol) per ISO 1407, drying to constant mass.
NBR latex: coagulation with ethanol/methanol and washing, then milling and drying per ISO 123.

Procedure: Typical test portion 50–500 mg (preferably 5–15 mg N), controlled digestion until clear blue‑green, steam distillation, photometric or potentiometric titration, blank correction.

Calculation: Formulas provided to convert titration volumes (using either sulfuric or hydrochloric acid) to bound acrylonitrile content (%).

Performance: Instrument accuracy must be demonstrated with reference material (ammonium sulfate) - system calibration and precision requirements are specified; interlaboratory precision data are reported in Annex B and C.

Applications and users

Who uses ISO 24698-2:2018:

Quality control and analytical laboratories in the rubber industry

NBR, XNBR and NBIR manufacturers and compounders

R&D teams developing nitrile elastomers and latex products

Suppliers verifying raw material composition for seals, hoses, gloves and fuel-resistant components

Regulatory and compliance testing where accurate acrylonitrile content is required

Practical uses:

Routine QC of acrylonitrile content to ensure material performance and consistency

Verifying latex coagulation and processing effects on bound acrylonitrile

Comparing results across production batches or suppliers using standardized Kjeldahl analysis

Related standards

ISO 24698‑1 (other methods for bound acrylonitrile)

ISO 1795 (sampling and prep for raw rubber)

ISO 123 (rubber latex sampling)

ISO 1407 (solvent extraction for rubber)

This summary helps labs and manufacturers understand when and how to apply ISO 24698‑2:2018 for reliable measurement of bound acrylonitrile in NBR and related materials.

ISO 24698-2:2018 PDF

Abstract

Похожие стандарты

Overview

Key topics and technical requirements

Applications and users

Related standards

Технические детали

ISO 24698-1:2018

Rubber, raw — Determination of bound acrylonitrile content in acrylonitrile-butadiene rubber (NBR) — Part 1:…

ISO 1795:2007

Rubber, raw natural and raw synthetic — Sampling and further preparative procedures

BS ISO 1407:2023

Rubber. Determination of solvent extract.

BS ISO 12312-3:2022

Eye and face protection. Sunglasses and related eyewear. Sunglasses for running, cycling and similar active l…