Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. इंटरनेट मानक “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “प0रा1 को छोड न’ 5 तरफ” Jawaharlal Nehru “Step Out From the Old to the New” “जान1 का अ+धकार, जी1 का अ+धकार” Mazdoor Kisan Shakti Sangathan “The Right to Information, The Right to Live” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 8979 (1997): Tetramethyl Thiuram Disulphide [PCD 13: Rubber and Rubber Products]
Transcript
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 8979 (1997): Tetramethyl Thiuram Disulphide [PCD 13:Rubber and Rubber Products]
IS 8979 : 1997
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h?TM~) Indian Standard
TETRAMETHYL THIURAM DISULPHIDE - SPECIFICATION
( Second Revision
ICS 83.040.2Oy 71.100.99
BUREAU OF INDIAN STANDARDS MAr\lAK BHAVAN, 9 BAHADLJR SHAH ZAFAR MARC
NEW DEI_HI 110003
Ruhbcr Producrs Sccrional Committee, PCD 13
This Indian Standard (Second Revision) wah adopted by the Bureau of Indian Srandardh, al’lcr lhc drail
linalizccl hy rhc Rubber Producls Sccrional Commiltec had hccn approved by the Pelrolcum, ( ‘o:rl :rrltl Kclatctl Producla Division Council.
Tcrramerhyl thiuram disulphidc is an ultra-Pds1 accelcralor f’or vulcanization 01 ruhhcr. When uxcd ;~ion~‘ with sulphur. specially in natural ruhhcr base stock, il ~cntls I(J hc rather scorch\. .I II is mol-c commonlv used as a booslcr or other acccIcra1ors or in non-clcmcntal hulphur cures (ct‘l’icicn~ Vulc;lnr/:riiorl (‘u1c.5 1.
‘l‘crr:lmethyl thiurum dixulphiclc is insoluhlc in water and slighUy sc)luhlc in hcwenc, and ~1lco11ol. 11 IS
solul~lc in chlorofi1rrx. Tclramcthyl Ihiuram dixulphrdc dihpcl-sc’ 111 ruhhcr wilhoul cl~f%c~ull~. IIt soluhiliiy in ruhhcr is approxini:ltcllv 0.125 pacnt h\, max5.
AS per the prcsenf atalc of knowlcdgc, Tclramcrhyl thiuram disulphide is approveI hy FDA (LISA) 101 use in rubber articlcs intended for rcpcatcd contacr with load provided Iota1 accclcrator conlent dock nol cxcced 1.5 pcrccnt hy weight of’ the rubber product. Howcvcr, thi\ ac‘cclerator is h:irmluI if sw;rII(t\~~~l and may C~USC skin irritation and scnGliLalion. Whilst ‘Thl’l’D is nor an ;tc‘ut~’ c*yc irricanl; pr,)longcd cxpo5urc may cau5c dcvclopment ofchr-onic conjuctiviti~.
This scan&I-cl was f’irsl published in 197X. The fir-sr rcvraion w;1> done in 1046 \\tth :I vice 01’ irlclurlc ;I mol-e accurate mclhod for determination of assay based on ultra violcr spa?ro\copy and included lhc rcquircnicnts and mcrhod lor dctcrmination of particle xi/e.
The Comniiltcc rccponsihle Car lhc prcpar;ition 01 this sl:ind:irtl tlccidcd I0 updalc il in the liyhi 01 cxpericncc gained. In this revision the assay of uncoatccl tclr:rmcth!‘l lhiuram tllsulphidc h;rs been tielc~c~cl and the quircmcnts of rna~lgmcsc have hccn modil’iai
Indian Standard
TETRAMETHYL THIURAM DISULPHIDE - SPECIFICATION
( Second Revision )
I scol’l~:
‘I‘his standard prescribes lhc rcquircmcnts iind
rncl t~ods 01' samplinji and test for tetramet hyl thiuram disulphidc (‘I’M’I‘D) intcndcd for USC as an ;lcccIcri~tor in ruhbcr compounds.
The following Indian Slandards contain provision which, through rcfcrencc in this text, constitute provisions of this standard. At the time of publica- tion, the editions indicated were valid. All stand- ards arc subject to revision and partics to ;igrcemcnts hascd on the standard arc cncouragcd to investigate the possibility of applying the most rcccnt editions of’thc standards indicated below:
IS h'o.
1070 : 19X.?
1075 : 1’171
IG-LJ : lCJ73
3?‘YLL : I973
3400
(P;trt I ) : 10x7
( IQ rt 2 ) : 1 W5
.300( 1
(Part 7) : IOSS
Title
Rcagcnt grade water - Specification (third twision)
Stcaric acid, technical (fir:sf rr,\Vsiotz)
Barytcs for rubber industry (_/ir:v/ rr3-ision )
Zinc oxide for rubber industl? (,\ cxw7d rcvisiot7 )
Methods of test for vulcanized rubbers: Tensile stress-strain properties (xecmci revision)
Dctcrmination of:rsh. rot;rl ct,p pc1-, m ;I n 2 a n c s c , I ubbcr hq.drocaI-bon. viscosity (Shear InSdi\k viscomctcr), 2nd mixing and vulcanizing ol rubber in 4t;tnd;~rd colll~wIId (/ir,\t
7080 (Part 1) : Methods of sampling and teal I 07J for rubber compounding iii-
grcdicnts : Part 1
3 HI’QUIKEMI~:N’I’S
The material shall bc in the form of a white to creamy white oil coated powder or pcllc~s, free from visible impurities.
3.2 The material shall also comply with the rc- quircmcnts given in Table 1 in conjunction with Annex A, when tested according to the method5 prescribed in col 4 and 5 of the Table 1.
3.3 Compounding Performance Requirement
The material when compounded and tcs~cd in ac- cordancc with Annex B shall have its pcrformancc comparable to that of the sample previously a11 proved by the purchaser.
4 PACKING ANI) MARKING
4. I Packing
The material shall bc packcd as a,grccd IO bctwccn the purchaser and Ihc supplier.
4.2 Marking
4.2. I The pchges hhall bc securely closed and Icgibty marked IO furnish the 10llow1n~ inli)r m;~ tion:
1s 8979 : 1997
4.2.3 The use of Standard Mark is governed by the 5.3 Criteria for Conformity provisions of the Bureau of Indian Standards Act, 1986 and the Rules and Regulations made there- The lot shall be considered as conforming to the
under. The details of conditions under which the specification if the composite sample satisfies each
liccnce for use of the Standard Mark may be granted one of the requirements.
to manufacturers or producers may be obtained 6 TEST METIIODS from Bureau of Indian Standards.
5 SAMPLING AND CRITERIA FOR 6.1 Test shall be carried out according to the CONFORMITY methods prescribed in Annexes A and B and the
5.1 Sampling Indian Standard as indicated in co1 5 of Table 1.
For the purpose of ascertaining the conformity of 6.2 Quality of Reagents tctramcthyl thiuram disulphide in a consignment to this specification, sampling as prescribed in 15 of Unless specified otherwise, pure chemicals and dis-
IS 7086 (Part 1) shall be followed. tilled water (see IS 1070) shall be cmploycd in
5.2 Number of Tests tests.
Tests for all characteristics shall be conducted on a NOTE - ‘Pure chemicals shall mean chemicals that do not contain impurities which affect the results of analysis.
composite sample.
Table 1 Requirements of Tetramethyl Thiuram Disulphide (TMTD) (Clauses 3.2 and 6.1)
SI No. Characteristic Requirement Methods of Ted, Ref lo
/ h \
Annex <:I No. ot of This Standard IS 6918
(1) (2) i) Assay (terramethyl thiuram disulphide
content), percent by mass, Min: a ) Ciranules b) Oil coated
II) Free amine, percent by mass, Mar
iii) Melting p<,int,‘CMirrr)
IV) Residue on 150.micron IS Sieve, percent by mass, MUX (in case of powders only)
(3)
95.0 96.0
0.5
145
0.5
(4) (5)
A
A
-
v) Loss on heating at 65’;: for 2 11, percent by mass, Mm
vi) Sulphated ash, percent by mass, Max
vii) Copper, ppm, Mar
vm) Manganese, ppm, Mm
0.5
0.5 -
20 -
20
A-3
A-4
A-S21
“In case ot dispute on melting point requirement. the final criteria for acrcptance shall he the assay requirement.
‘)ln this cast. the temperature of the oven is to be kept at 65kl”C instead of lOSt2”C.
2
IS 8979 : 1997
ANNEX A
[Cluuses 3.2 and 6.1, and Tuble 1, SZ No. (i) and (ii)]
DETERMINATION OF ASSAY AND FREE AMINE CONTENT OF TETRAMETHYL THIURAM DISULPHIDE
A-O GENERAL
Three methods, Method I, Method II and Method III are given. For routine work, the first two methods may be followed while for more accurate work, spectroscopic method given later should be followed which will also be the referee method in case of dispute. Free amines are determined by Method I only.
A-l METIIOD I
A-l.1 Principle
A solution of the substance is reduced with hydrogen sulphide and the liberated amine is titrated with acid.
A-l.2 Reagents
A-1.2.1 Solvent Mixture - isopropanol-toluene mixture in the ratio of .5:3.
A-1.2.2 Standard Hydrochloric Acid Solution - 0.1 N and 0.5 N.
A-1.2.3 Sodium Hydroxide Solution - 0.1 N.
A-1.2.4 Brotnophenol Blue Solution - 1 percent solution in ethanol.
A-l .3 Apparatus
A-1.3.1 Kipps Apparatus - for hydrogen’sulphide generation.
A-l.4 Procedure
Weigh accurately 1.5 g of substance into 500-ml conical flask. Add 150 ml of isopropanol-toluene mixture to dissolve the material, slightly warming the Ilask, if necessary. Titrate any free amine with 0.1 N hydrochloric acid using bromophenol blue indicator. Ncutralizc with a few drops of 0.1 N sodium hydroxide and pass hydrogen sulphide through the same for 15 minutes. Titrate the lihcrated amine with 0.5 N hydrochloric acid.
A- 1.5 Calculations
‘4-1.5.1 Tetramethyl thiuram BXG =-
disulphide, percent by mass M
A-l S.2 Free amine, Ax4Sx6 percent by mass = hP x 1 ooo
3
where A =
B =
M=
ml of 0.1 N hydrochloric acid required in the first titration; ml of 0.5 N hydrochloric acid required in the second titration; and mass of the sample in g taken for the test.
NOTE - 1 ml of 0.5 N Hydrochloric Acid = 60 mg of tetramethyl thiuram disulphide.
A-2 METIIOD II
A-2.1 Principle
Tetramethyl thiuram disulphide on digestion with a dilute mineral acid undergoes decomposition and yields a salt of dimethylamine. After boiling off the volatile sulphur compounds, the amine is liberated by steam distillation under alkaline condition and estimated by titration with a standard acid.
A-2.2 Reagents
A-2.2.1 StandardHydrochloricAcid Solution -0.2 N.
A-2.2.2 Boric Acid Solution
20 g per litre. Each litre of solution shall also contain 10 ml of 0.05 percent methyl red and 0.7 ml of 0.35 percent methylene blue solutions.
A-2.2.3 Sul’huricAcid Solution - approximately 5
M.
A-2.2.4 Sodium Hydroxide Solution - ap- proximately 5 M.
A-2.2.5 Methyl Red Indicator Sotufion - 0.5 per- cent.
A-2.3 Apparatus
A simple apparatus for steam distillation consists of two one-litre flat-bottomed flasks. One of lhc flasks used as ‘steam generator’ is provided with a long safety tube dipping well below the surface 01. water and a steam outlet tube. The other lle\k in which steam distillation is carried out is provided with a dropping funnel, a steam inlet ruhc which is connected to the steam outlet tuhc of the SIC:I~ generator and a steam outlet tube which in its turn is conncctcd to a water-cooled upright Licbig COII dcnscr through a splash head. The distillate I‘rom the condenser is collcctcd in a X)0-ml conical flask by dipping the bottom end of the I,icbig condenser
1s 8979 : 1997
below the liquid surface in the conical flask placed in a cold bath.
A-2.4 Procedure
Weigh accurately about 0.5 to 0.8 g of the prepared sample into a 150 ml round bottomed flask and add to it SO-ml of 5 M sulphuric acid. Attach a water- cooled reflux condenser to the flask .and heat the contents slowly to boiling with occasional shaking. Allow to reflux for one hour, cool and transfer the contents quantitatively into the distillation flask of the steam distillation assembly. Steam distil until 200-m] of distillate is collected. Stop the distilla- tion and reject the distillate which contains carbon disulphide, etc. Add a few drops for methyl red indicator into the contents of the distillation flask followed by 7.5 M sodium hydroxide solution until alkaline, add 10 to 15 ml in excess and steam distil the liberated amine. Collect about 250-m] of distil- late in the receiver containing 50-ml of boric acid solution and titrate with 0.2 N hydrochloric acid to violet end point. Carry out a blank test on the reagents.
A-2.5 Calculation
Tetramethyl thiuram disulphide,
percent by mass = ( T2 - TI) F x 2.404
M where
T2 = ml of 0.2 N hydrochloric acid required for blank,
Tl = ml of 0.2 N hydrochloric acid required for sample,
F = factor of 0.2 N hydrochloric acid, and M = mass in g of sample taken.
A-3 METHOD III - SPECTROPHOTOMETRIC METIIOD
A-3.1 Apparatus
Ultra Violet Spectrophotometer - Any standard instrument with the following provisions:
a> b)
4 d) e)
A-3.2
Range 150 nm to 500 nm, Wavelength accuracy of not less than 0.2 nm, Wavelength scan facility, Recorder with speed control, and Method UV cells (silica) - 1 cm path length - 2 pairs with teflon caps.
Reagents
1\-3.2.1 Isopropyl Alcohol
A-3.2.2 Methylene Dichloride
NOTE-Both solvents should be ofspectroscopic grade. In case such grade is not available, any grade for which the absorbance in a l-cm UV cell (with air as reference) is less than 0.04 may be used.
A-3.2.3 0.8 percent solution of methylene dichloride in iso-propyl alcohol (v/v).
A-3.3 Procedure
A-3.3.1 Prepare a representative sample by taking about equal amounts from each sample container and mixing thoroughly. If the material is pelleted, crush the pellets before mixing. Weigh accurately 50 + 3 mg of sample into a clean, dry, tared weigh- ing funnel. Transfer the sample into a lOO-ml volumetric flask (which has been thoroughly cleaned and rinsed with iso-propyl alcohol) by washing the sample through a funnel into the flask with lo-ml methylene dichloride. Swirl the con- tents until all the sample has dissolved, then pour 80 ml of iso-propyl alcohol through the weighing funnel into the flask. Make the volume up to lOO- ml mark with iso-propyl alcohol by means of a dropping pipette. Stopper the flask and shake the contents until the solution is well mixed.
A-3.3.2 Wash out a clean dry lo-ml pipette with this solution, rejecting the washings. Pipette IO-ml of fresh solution into a clean 100-ml volumetric flask which has been rinsed with iso-propyl alcohol, taking every care to pipette an accurate volume. Make the volume up to lOO-ml mark with iso- propyl alcohol by means of a dropping pipette. Stopper the flask and shake the contents until the solution is well mixed.
A-3.3.3 Fill two cells with a 0.8 percent (v/v) solu- tion of methylene dichloride in iso-propyl alcohol. Put them in the ‘sample’and ‘reference’cell holders of the instrument. By controlling the ‘zero knob’, ensure that the absorbance in the 200-350 nm region remains zero. A scan on the records will indicate the actual variation; the absorbance line should merge with the chart base line. In any case, it is essential that at the specified wavelength (1) for measurement of actual sample (see subsequent sec- tions), the absorbance should be absolutely zero. Once the zero setting is done, do not touch the knob.
NOTE-Before putting UVcells m the holders, always hold them on the ground surfaces and wipe the transparent sur- faces clean dry with soft tissue paper.
A-3.3.4 Take out the cell from the ‘sample’ holder, throw the solvent, dry the cell, rinse 4-5 times with the test solution, fill it up, put the cap, wipe clean the outer surfaces, and place it back in the holder. Do the wavelength scan at the slowest convenient speed between 200-350 nm. Measure accurately the absorbance (A) between the peak maximum and base line at the specified wavelength (in this case 275 nm).
NOTE - The shape of the absorbance curve should bc stmilar to that of a standard sam@e.
4
IS 8979 : 1997
1\-3.3.5 Srrrntlrrrrl S~ntpk md hwc Mntrrirrl -- In cast the absorption cocfficicnt (E) of the ac- cclcrator is unknown, prepare a pure sample by recrystallizing at least 5 times from a solution of it in a suitable solvent. Prcscrve the final rccrystall- i/.cd aamplc in f xcalcd tuhc or under nitrosen in a rcl’rigcrator. Dctcrminc the absorblrncc (Ao) fol- lowing the proccdurc A-3.3.3.
A-3.4 CillCIll:ltiOll
A “=ct
where /-I = absorbance of accelerator solution, C = concentration of the solution in
gjlitres, and I = path length = 1 cm.
100 A Active ingredient (percent) = c~
100 ACo
AoC where Co is the concentration of pure ;1ccclcr;1to1 solution.
ANNEX B
hlI~Xl10l) l+WIt COhll’OUNI)ING AND 1’F:S’L’ING Ok
~I‘l~I‘l~ARfl”l’lI~I, ‘I’IlIURh~~ I)1SUL1’1111)1’
II- I ‘I’I’SI’ CORI 1’011 N I)
lL1.1 As 3 guidrncc, the following test compound ni;~y bc used l’or tearing pcrform:rnce properties of tctr;imci hyl thiuram clisulphidc in rubber com- pwlrlds:
Zinc oxide (SW IS 3399) 5
Stearic :tcid (SW IS 1075) I
I32lyc:s (.s(‘c IS lOS3) 75
Sulphur (ruhhcr grade) 2
Tctramcthyl thiurnm tlisulphidc 0.5
B-2 COI\II’OUNI)IN(;
K-2.1 Follow the procedure prcscribcd in IS 3660 (f’;11-I 51).
11-3 ‘I’I’S’I‘S
bc tested side by side using the same master hatch, that is, compound excluding accclcrator only.
11-3.1.1 Mooney scorch test shall hc done at 110°C’ in accordance with the method prcscribcd in NK:S 01‘ IS 3660 (Part 7).
U-3.1.2 Tensile strength, modulus :tt 300 pcrccnt clongalion and elongation at break at diffcrcnt cures (for example 5, 7.5, 10 and 12 minutes) at 141°C: from below to above the expcctcd optimum curt shall bc tested in accordance with the method prescribed in IS 3400 (Part 1).
R-3.1.3 Hardness on optimum cure at 141°C shall be tested in accordance with the method prcscribcd in IS 3-IOU (Part 2).
H-4.1 The values obtained with the test sample shall not vary by more than -+20 percent 1’01
Mooney scorch and + 1U percent for all the other characteristics l’rom those obtained with the stand- :rrd xamplc.
Bureau of Indian Standards
BIS is a statutory institution established under the Bureau of Indian Sandurds Act, 19S6 to promote harmonious development of the activities of standardization, marking and quality cerlit’ication oi goods and attending to connected matters in the country.
Copyright
BIS has the copyright of all its publications. No part of these publications may he reproduced in any I.ornl without the prior permission in writing of BIS. This dots not prccludc the fret USC, in the course 01 implementing the standard, of necessary details, such as symbols and sizes, type or grade dcsign.lliorls Enquiries relating to copyright be addressed to the Director (Publication), BIS
Review of Indian Standards
Amendmenls arc issued lo sl;mdards as the need arises on the basis of cornmen&. St;~nthrds arc also rcvicwccl
periodically; a standard along with amcndmcnts is reaffirmed when such rcvicw indicates that no ch:tngcx ;lrt’
nccdcd; if’ the rcvicw indicates that changes arc nccdcd, it is taken up l‘or revision. llscrs of Indian SLlrxkrrd.4 should ascertain that they arc in possession of the latest amcndmcnts or edition by rcfcrring to the 1atcst ihsuc of ‘BIS Handbook’ and ‘Standards Monthly Additions’.
This Indian Standard has been developed from Dot: No. PCD 1.3 ( 1325 ).
Amend No.
Amendments Issued Since Publication
Date of Issue Text Aft&d-
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