ISO 21490 pdf download

ISO 21490 pdf download Rubber and rubber products — Determination of 2-mercaptobenzothiazole content by high performance liquid chromatography (HPLC)
This document specifies a quantitative test method to determine the 2-mercaptobenzothiazole contentin rubber and rubber products by high performance liquid chromatography (HPLC).
This document delivers a method for quantifying 2-mercaptobenzothiazole in rubber products for abetter selection of curing conditions.
This document provides a method to follow the curing of rubber with sulfur- and benzothiazole-based accelerators using a chemical measurement which is complementary to the classical rheometrictechnique.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO 3696, Water for analytical laboratory use — Specification and test methods
IS04661-2, Rubber, vulcanized — Preparation of samples and test pieces — Part 2: Chemical tests
3Terms and definitions
No terms and definitions are listed in this document.
IS0 and IEC maintain terminology databases for use in standardization at the following addresses:-ISo Online browsing platform: available at https://www.iso.org/obp
—IEC Electropedia: available at https://www.electropedia.org/
4 Principle
The 2-mercaptobenzothiazole in rubber is ultrasonically extracted with a chloroform-methanol solutiondetermined and confirmed with HPLC-DAD(high performance liquid chromatography equipped with adiode-array detector).
Note There is a risk of neo-formed MBT from MBTs if a thiazole accelerator is used in the formulation of thesample.
5 Reagents and materials
Unless otherwise specified, analytical grade chemicals should be used. Water shall be distilled ordeionized to fulfil grade 3 in accordance with ISo 3696.
5.1 Methanol, of analytical grade.
5.2 Chloroform, of analytical grade.
5.3 Acetonitrile, of chromatographic grade.
5.4 2-Mercaptobenzothiazole standard material, of purity ≥ 99,1 %.
5.5 Filtration membrane, with a pore size of 0,45 µm.
5.6 Chloroform-methanol solution, 2 V+1 V.
6 Apparatus
The usual laboratory apparatus and, in particular, the following shall be used.
6.1 HPLC-DAD.
6.2 Analytical balance, accuracy ± 0,1 mg.
6.3 Ultrasonic extraction apparatus.
6.4? One-mark? volumetric? flask, 100 ml.
6.5? Quantitative? filter? paper.
6.6 Flask with stopper, 20 ml.
6.7 Pipette, 10 ml.
7 Sampling
Prepare the sample according to ISO 4661-2, cut it into pieces smaller than 0,1 cm × 0,1 cm. Store the ample pieces in a dry and cool place, and avoid their contamination.
8 Procedure
8.1 Sample preparation
Weigh approximately 0,4 g (accurate to 0,1 mg) of a homogeneous test sample and put it into a 20 ml flask with a stopper. Add accurately, by pipette, 10 ml chloroform-methanol solution (5.6) and stopper the flask. Extract for 14 h in the ultrasonic extraction apparatus (6.3) at a temperature not exceeding 40 °C.
In order to maintain the bath below 40 °C, it is necessary to periodically add cold water or another cooling agent to the bath during the extraction.
Transfer the extracted solution into a 100 ml volumetric flask (6.4) with funnel and filter paper (6.5),dilute it to the mark with methanol and mix thoroughly.