ISO/TC 45/SC 3/WG 5 - Synthetic and reclaimed rubber

This document specifies two methods for the determination of volatile-matter content in raw rubbers by using a hot mill or an oven. These methods are applicable to the determination of the volatile-matter content in the “R” group of rubbers listed in ISO 1629. These are rubbers having an unsaturated carbon chain, for example natural rubber and synthetic rubbers derived at least partly from di-olefins. These methods can also be applicable to other raw rubbers, but in these cases it is necessary to demonstrate that the change in mass is due solely to loss of actual volatile matter and not to rubber degradation. The hot-mill method is not applicable to natural rubber, to synthetic rubbers which are too difficult to handle on a hot mill or to synthetic rubbers in powder or chip form. The two methods do not necessarily give identical results. Therefore, in the case of dispute, the oven method, procedure A, is the reference method. NOTE      The applicability of each test method to various types of rubber is summarized in Annex A.

This document specifies: — the physical and chemical tests on raw rubbers, and — the standardized materials, a standardized test formulation, equipment, and processing methods for evaluating the vulcanization characteristics of all types of isobutene-isoprene rubber (IIR).

This document specifies: — the physical and chemical tests on raw rubbers; — the standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of ethylene-propylene-diene rubbers (EPDM), including oil-extended types.

This document specifies: — the physical and chemical tests on raw rubbers; — the standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of styrene-butadiene rubber masterbatches with carbon black or with carbon black and oil.

This document specifies, for acrylonitrile-butadiene rubbers (NBRs): — physical and chemical tests on raw rubbers; — standard materials, a standard test formulation, equipment and processing methods for evaluating the vulcanization characteristics. The mixing preferred method is the single stage mixing with LIM (laboratory internal mixer).

This document specifies a method using a differential scanning calorimeter to determine the glass transition temperature of raw rubber and rubber latex.

This document specifies a method for determining the bound styrene content of emulsion-polymerized styrene-butadiene rubbers (SBR) by correlation with the measured refractive index of an extracted sample according to a table of refractive indices versus percentage mass fractions styrene. The method is also applicable to extracted oil-extended emulsion-polymerized SBR as long as it produces a film suitable for refractive index measurements. It is not applicable to solution-polymerized SBR.

1.1 This document specifies two thermogravimetric methods for the determination of moisture and other volatile-matter content in raw rubbers by using an automatic analyser with an infrared drying unit. 1.2 These methods are applicable to the determination of volatile-matter content in synthetic rubbers (SBR, NBR, BR, IR, CR, IIR, halogenated IIR and EPDM) listed in ISO 1629 and to various forms of raw rubber, such as bale, block, chip, pellet, crumb, powder and sheet. These methods might also be applicable to other raw rubbers only when the change in mass is proven to be due solely to loss of original volatile matter and not to rubber degradation. 1.3 The methods are not applicable to raw rubbers which need homogenizing as specified in ISO 1795. 1.4 The hot-mill method and the oven method specified in ISO 248‑1 and the methods specified in this document might not give identical results. In cases of dispute, therefore, the oven method, procedure A, specified in ISO 248‑1:2011, is the referee method. NOTE These methods can be useful for routine determinations, e.g. quality control, when the measurement conditions for the automatic analyser are fixed for a particular raw rubber or grade of raw rubber.

This document specifies, for general-purpose non-oil-extended, solution-polymerized polyisoprene rubbers (IR): — physical and chemical tests on raw rubbers; — standard materials, a standard test formulation, equipment and processing methods for evaluating the vulcanization characteristics.

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.

This document specifies a method for the determination of the bound acrylonitrile content in NBR by an automatic analyser which uses a combustion process. 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 24698‑2 can give different results on the same rubber sample.

ISO 7781:2017 specifies three methods for the determination of the soap and organic-acid content of raw styrene-butadiene rubber (SBR). - Method A is the titration method using indicator reagent. - Method B is the titration method using an automatic potentiometric titrator. - Method C is the back titration method using an automatic potentiometric titrator. Since the soaps and organic acids present in the rubber are not single chemical compounds, the method gives only an approximate value for the soap and organic-acid content.

ISO 1795:2017 specifies a method for the sampling of raw rubber in bales, blocks or packages and further procedures carried out on the samples to prepare test samples for chemical and physical tests.

ISO 19846:2017 specifies: - a coding system of reclaimed natural rubber and reclaimed isobutylene-isoprene (IIR) rubber; - a numeric system to classify reclaimed rubber.

ISO 11344:2016 describes a method for the determination of the molecular mass, expressed as polystyrene, and the molecular-mass distribution of polymers produced in solution which are completely soluble in tetrahydrofuran (THF) and which have a molecular-mass range from 5 × 103 to 1 × 106. It is not the purpose of this International Standard to explain the theory of gel permeation chromatography.

ISO 6235:2016 specifies a method for the determination of the long polystyrene block content of raw uncompounded styrene-butadiene rubber (SBR) and raw uncompounded blends of block SBR. It is not applicable to blends of block SBR with EPDM, IIR, CSM and other halogenated rubbers. The method is applicable to raw, uncompounded latices of the above compositions and is suitable for rubbers having block polystyrene contents in the range from 5 % (by weight) to 100 % (by weight). Rubbers having block polystyrene contents of less than 5 % (by weight) may yield incorrect results unless a correction factor, based on information gained by working with such rubbers, is applied. The method is intended for use on gel-free rubbers, but it may be used on rubbers containing gel if it has been proved that the gel does not interfere.

ISO 14558:2016 specifies a method for determining the residual unsaturation in hydrogenated nitrile rubber (HNBR) by measuring the infrared (IR) absorbance of HNBR films cast from solution. ISO 14558:2016 assumes that samples and IR spectra are prepared and analysed by experienced personnel and that equipment is operated in accordance with the manufacturer's instructions. Details for operating an IR spectrometer are not included in this method.

ISO 21561-2:2016 specifies procedures for the quantitative determination of the microstructure of the butadiene and the content of styrene in solution-polymerized SBR (S-SBR) by Fourier Transform Infrared Spectrometry (FTIR) with Attenuated Total Reflection (ATR) method. The styrene content is expressed in mass % relative to the whole polymer. The vinyl, trans and cis contents are expressed in mol % relative to the butadiene content. This method is only applicable to raw rubbers. NOTE 1 Precision as shown in Annex A may not be obtained for S-SBRs containing polystyrene block or styrene content more than 45 mass %. NOTE 2 Only "vinyl", "trans" and "cis", are used in this part of ISO 21561. However, the expression of vinyl, trans and cis mean as follows in general: - vinyl: vinyl unit, vinyl bond, 1,2-unit, 1,2-bond, 1,2-vinyl-unit or 1,2-vinyl-bond; - trans: 1,4-trans unit, 1,4-trans bond, trans-1,4 unit or trans1,4 bond; - cis: 1,4-cis unit, 1,4-cis bond, cis-1,4 unit or cis-1,4 bond.

ISO 20299-1:2015 specifies the material and physical property requirements for non-strippable film for wrapping general-purpose synthetic rubber bales, intended to keep the bales separate during storage, for example for wrapping: ? styrene-butadiene rubber (SBR); ? butadiene rubber (BR). Certain applications or processing methods require the removal of the film. This part of ISO 20299 does not deal with strippable films.

ISO 21561-1:2015 specifies procedures for the quantitative determination of the microstructure of the butadiene and the content of styrene in solution-polymerized SBR (S-SBR) by 1H-NMR spectrometry as an absolute method and by IR spectrometry as a relative method. The styrene content is expressed in mass % relative to the whole polymer. The trans, cis and vinyl contents are expressed in mol % relative to the butadiene. These methods are applicable only for raw rubber. NOTE 1 IR spectrometry can also give absolute values of microstructure by calibration with S-SBRs of known absolute microstructure obtained by 1H-NMR spectrometry. NOTE 2 Only "vinyl", "trans" and "cis" are used in this part of ISO 21561. However, the expression of vinyl, trans and cis mean as follows in general: - vinyl: vinyl unit, vinyl bond, 1,2-unit, 1,2-bond, 1,2-vinyl-unit or 1,2-vinyl-bond; - trans: 1,4-trans unit, 1,4-trans bond, trans-1,4 unit or trans1,4 bond; - cis: 1,4-cis unit, 1,4-cis bond, cis-1,4 unit or cis-1,4 bond.

ISO 7663:2014 specifies the following: - physical and chemical tests on raw rubbers; - standardized materials, a standardized test formulation, and the equipment and processing methods for evaluating the vulcanization characteristics of all types of halogenated isobutene-isoprene rubber (BIIR and CIIR).

ISO/TS 16095:2014 defines - the physical and chemical tests on raw reclaimed natural rubber, and - the standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics, and the mechanical properties of reclaimed natural rubber.

ISO/TS 16096:2014 specifies - physical and chemical tests on raw reclaimed isobutene-isoprene (IIR) rubber, and - standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics and the mechanical properties of reclaimed isobutene-isoprene rubber.

ISO 2476:2014 specifies: - physical and chemical tests on raw rubbers; - standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of solution-polymerized butadiene rubbers (BR), including oil-extended types (OEBR), and the tensile stress-strain properties of vulcanized mixes.

ISO 2322:2014 specifies: - physical and chemical tests on raw rubbers; - standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of emulsion- and solution-polymerized styrene-butadiene rubbers (SBR), including oil-extended rubbers.

ISO/TS 16097:2013 specifies physical and chemical tests, standard test formulations, equipment and processing methods for the vulcanization-characteristics evaluation and the mechanical properties of vulcanized crumb rubber. It is not aimed to provide specifications or limitations, or whether these vulcanized crumb rubbers may be used.

ISO 16565:2013 specifies the methods to be used to determine the content of 5 ethylidenenorbornene (ENB) or dicyclopentadiene (DCPD) in ethylene-propylene-diene (EPDM) terpolymers in the 0,1 % to 10 % range. ENB and DCPD are dienes introduced into ethylene-propylene rubbers to generate specific cure properties. Since high precision for diene content determination is important, a Fourier transform infrared spectroscopic (FT IR) method is utilized.

ISO 12492:2012 specifies a test method for the determination of water content of raw rubber and compounded rubber using a coulometric Karl Fischer titration method. It applies to the range for the water content between 0,01 % and 1 %. As this is a very sensitive method, contact of sample with any moisture, even from the surrounding environment, must be eliminated as much as possible.

ISO/TR 16098;2012 specifies standard materials, standard test formulations, equipment and processing methods for evaluating the dispersion of reclaimed rubbers and reclaimed crumb rubbers in rubber mixes.

ISO 2475:2011 specifies, for general-purpose chloroprene rubbers (CRs): physical and chemical tests on raw rubbers; standard materials, standard test formulations, equipment and processing methods for evaluating the vulcanization characteristics.

ISO 11089:2010 describes a procedure for the determination of the following antidegradants in raw synthetic rubbers: N‑alkyl-N'‑phenyl-p‑phenylenediamine; N‑aryl-N'‑aryl-p‑phenylenediamine; poly‑2,2,4‑trimethyl-1,2‑dihydroquinoline. Extender oils, when present, can interfere. The method, with modification if necessary, can be applied to the determination of other amine antidegradants.

ISO 17564:2008 specifies a method using Wijs' solution to determine the iodine value (i.e. the residual unsaturation) of raw hydrogenated nitrile rubber (HNBR).

ISO 17052:2007 specifies a method for the determination of residual monomers and other volatile low-molecular-mass compounds in raw rubber by capillary column gas chromatography using a thermal desorption (also known as dynamic headspace) method. It includes a generic section that is applicable to all types of raw rubber and two annexes specific to particular rubber types. This method has the advantages of not requiring a solvent, of concentrating the volatile compounds and of introducing them to the chromatograph in a very precise manner. The compounds found in the raw rubber which are to be determined are defined as residual monomers, solvents and other low-molecular-mass compounds in the boiling point range of C4 to C12 hydrocarbons. NOTE The limit of detection is 1 microgram per gram.

ISO 22768:2017 specifies a method using a differential scanning calorimeter to determine the glass transition temperature of raw rubber.

ISO 2302:2014 specifies physical and chemical tests on raw rubbers and standardized materials, a standardized test formulation, equipment, and processing methods for evaluating the vulcanization characteristics of all types of isobutene-isoprene rubber (IIR).

ISO 4659:2014 specifies physical and chemical tests on raw rubbers; standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of styrene-butadiene rubber masterbatches with carbon black or with carbon black and oil.

ISO 4097:2014 specifies physical and chemical tests on raw rubbers; standard materials, standard test formulations, equipment, and processing methods for evaluating the vulcanization characteristics of ethylene-propylene-diene rubbers (EPDM), including oil-extended types.

ISO 248-1:2011 specifies two methods for the determination of volatile-matter content in raw rubbers by using a hot mill or an oven. The methods are applicable to the determination of the volatile-matter content in the "R" group of rubbers listed in ISO 1629. These are rubbers having an unsaturated carbon chain, for example natural rubber and synthetic rubbers derived at least partly from diolefins. The methods can also be applicable to other raw rubbers, but in these cases it is necessary to demonstrate that the change in mass is due solely to loss of actual volatile matter and not to rubber degradation. The hot-mill method is not applicable to natural rubber, to synthetic rubbers which are too difficult to handle on a hot mill or to synthetic rubbers in powder or chip form. The applicability of each test method to various types of rubber is summarized in an annex.

ISO 2303:2011 specifies, for general-purpose non-oil-extended, solution-polymerized polyisoprene rubbers (IR): physical and chemical tests on raw rubbers; standard materials, a standard test formulation, equipment and processing methods for evaluating the vulcanization characteristics.

ISO 2322:2009 specifies: physical and chemical tests on raw rubbers; standard materials, standard test formulations, equipment and processing methods for evaluating the vulcanization characteristics of emulsion- and solution-polymerized styrene-butadiene rubbers (SBR), including oil-extended rubbers.

ISO 2476:2009 specifies: physical and chemical tests on raw rubbers; standard materials, standard test formulations, equipment and processing methods for evaluating the vulcanization characteristics of solution-polymerized butadiene rubbers (BR), including oil-extended types (OEBR), and the tensile stress-strain properties of vulcanized mixes.

ISO 24698-1:2008 specifies a method for the determination of the bound acrylonitrile content in NBR by an automatic analyser which uses a combustion process. The method is also applicable to NBR latex.

ISO 24698-2:2008 specifies a method for the determination of the bound acrylonitrile content in NBR by an automatic analyser which uses the Kjeldahl method.

ISO 7781:2008 specifies methods for the determination of the soap and organic-acid content of raw styrene-butadiene rubber (SBR). Method A is the titration method using indicator reagent. Method B is the titration method using an autotitrator or pH-meter. The methods depend on the extraction of the organic acids and soaps from the rubber by means of a specified solvent. In practice, therefore, it is convenient to determine both organic-acid and soap contents on separate portions of the same solvent extract. Since the soaps and organic acids present in the rubber are not single chemical compounds, the method gives only an approximate value for the soap and organic-acid content.