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1 Quantitative Second estimation level of Anti-degradants in tyre components Presented by Tirthankar Bhandary 1

2 Degradation of polymer BACKGROUND Reaction of anti-degradant Possibility of resonance of radical present in Ǻ loses the reactivity of the radical and prevents propagation of the reaction. 2

3 MOTIVATION OF WORK Rubber, being a organic materials and contains un-saturation, are susceptible to weather attack. To protect rubber products from such weather degradation, different types of antioxidants / antiozonants are added in rubber compounds. While service of rubber products these anti-degradants are getting consumed It is one of the important requirement to identify as well as quantify the level of anti-degradants present in rubber product to assess Failure mode of the rubber product Development of new compound with better weather resistance criteria Service life of the rubber products These are the motivation of qualitative and quantitative estimation of antidegradants in rubber products. 3

4 SCOPE OF WORK In the present work three types of very common anti-degradants used in tyre industry are selected, viz. TMQ (2,2,4-Trimethyl-1,2-Dihydroquinoline) 6PPD (N(1,3-dimethyl-butyl)-N'-phenyl-P-phenylenediamine) DTPD; Mixture of DPPD (N,N'-diphenyl-p-phenylenediamine) DTPD (N,N'-ditolyl-p-phenylenediamine) TPPD (N tolyl-n -phenyl-p-phenylenediamine 4

5 METHODOLOGY Identify the presence of anti-degradants using GC-MS Draw a calibration Second curve level using different of re-crystallized antidegradants under quantification Estimation of the anti-degradants present in extracted sample by GC-MS 5

6 GC-MS PRINCIPAL GC separates a mixture into individual substances depending on the boiling point and polarity of the substances Mass spectrometer identifies the mass to charge (m/z) ratio of substances. 6

7 GC Chromatograms of identified anti-degradant 7

8 ANALYSIS OF RECRYSTALLIZED TMQ Chromatogram of TMQ Mass spectra of TMQ 8

9 ANALYSIS OF RECRYSTALLIZED 6PPD Chromatogram of 6PPD Mass spectra of 6PPD 9

10 ANALYSIS OF RECRYSTALLIZED DTPD Chromatogram of DTPD Mass spectra of DPPD 1

11 ANALYSIS OF RECRYSTALLIZED DTPD Mass spectra of PTPD Mass spectra of DTPD 11

12 Generation of calibration curves for different anti-degradant 12

13 GENERATION OF CALIBRATION CURVES : METHODS Mixture of 3 different three different s Run the samples Second in GC-MS level in Selective Ion Mode (SIM) Draw calibration curve by plotting Area under the curve Vs Conc Area Under the curve obtained for each conc of respective anti-degradants Calibration Co-relation Factor ( R 2 ) : Min.99 13

14 Concentration (mg/25 ml) CALIBRATION CURVE FOR TMQ.75 Calibration curve for TMQ y =.11x R² = Area under the curve

15 Concentration (mg/25 ml) CALIBRATION CURVE FOR 6PPD y = 1E-5x R² = 1. Calibration curve for 6PPD _ 4 _ Area under the curve 15

16 Concentration (mg/25 ml) CALIBRATION CURVE FOR DTPD y = 3E-5x R² =.9999 Calibration curve for DTPD _ 4 _ Area under the curve 16

17 Concentration (mg/25 ml) Concentration (mg/25 ml) STABILITY OF STANDARD SOLUTION: DTPD y = 3.E-5x R² = Week-1 Area under the curve Week-3 y = 2.79E-5x R² = Area under the curve y = 2.99E-5x R² =.998 Week Area under the curve Week-4 y = 2.61E-5x R² = Area under the curve 17

18 Analysis of sample Second containing level mixture of anti-degradants 18

19 Concentration (mg/25 ml) Recovery (%) ANALYSIS OF KNOWN TMQ SAMPLE High Medium Tested result Actual value Recovery Low Recovery (%) = Sample Id High Medium Low Actual (mg/25ml) Measured value Actual Value Recovery values : Between 93-11% Calculated (mg/25 ml) X 1 Recovery (%)

20 Concentration (mg/25 ml) Recovery (%) ANALYSIS OF KNOWN 6PPD SAMPLE Calculated conc Actual conc Recovery 12 1 Recovery (%) = Measured value Actual Value X High Medium Low Sample Id High Medium Low Recovery values : Between 94-14% Actual (mg/25ml) Calculated (mg/25 ml) Recovery (%)

21 Concentration (mg/25 ml) Recovery (%) ANALYSIS OF KNOWN DPPD SAMPLE Click to edit Master 8 text Between styles 86-11% High Medium Tested result Actual value Recovery 6 Low Recovery (%) = Sample Id High Medium Low Recovery values : Actual (mg/25ml) Measured value Actual Value Calculated (mg/25 ml) X 1 Recovery (%)

22 Analysis of cured rubber containing anti-degradants 22

23 ESTIMATION OF ANTI-DEGRADANTS IN CURED RUBBER: METHOD Cured rubber samples Extract containing anti-degradants Run in GCMS in SIM Mode Quantify anti-degradants content using calibration curve 23

24 Antioxidant content (%) Recovery (%) COMPOUND Tested result Actual value Recovery Recovery (%) = Measured value Actual Value X Between 8-118% TMQ 6PPD 8 DPPD Antioxidant TMQ 6PPD DPPD Recovery values : Actual (mg/25ml) Calculated (mg/25 ml) Recovery (%)

25 Antioxidant content (%) Recovery (%) COMPOUND-2 Tested result Actual value Recovery TMQ 6PPD DPPD Recovery (%) = Antioxidant TMQ 6PPD DPPD Actual (mg/25ml) Measured value Actual Value Recovery values : Between 85-16% Calculated (mg/25 ml) X 1 Recovery (%)

26 METHOD VALIDATION Following steps has been performed to validate the test method: 1. Linearity 2. Repeatability 3. Recovery 4. Estimation of Limit of detection 5. Estimation of Limit of quantification 26

27 Concentration (mg/25 ml) Concentration (mg/25 ml) Concentration (mg/25 ml) R² = TMQ 4.98 LINEARITY Area under the curve R² = Fourth DTPD level 7.7 R² = PPD Area under the curve Area under the curve 27

28 Standard deviation Standard deviation Standard deviation TMQ.3 8.2, ,.3 5.,.3. TMQ Content (mg/25ml) _ DTPD ,.23 REPEATABILITY 3.5, , DTPD Content (mg/25ml) ,.4 6PPD 6.61, , PPD Content (mg/25ml) Repeatability at 95% confidence level is defined as: 2.83 X Standard deviation 28

29 Actual value (mg/25ml Actual value (mg/25ml Actual value (mg/25ml LIMIT OF DETECTION & QUANTITATION Click to edit 2 Master text styles.62 1 _ 6.56 _ TMQ Measured value (mg/25ml) DTPD 1.64 Measured value (mg/25ml) Anti- degradant PPD Measured value (mg/25ml) Slope 2 Std Deviation LOD (mg/25ml) LOQ (mg/25ml) TMQ PPD DTPD LOD = 3.3 X std deviation at lowest /slope LOQ= 1. X std deviation at lowest /slope Ref: Chronicles of Young Scientists, Vol. 2 Issue 1 Jan-Mar 211, DOI: 1.413/

30 SUMMARY AND CONCLUSIONS: Recovery (%) of 9-11% on the samples containing mixture of different anti-degradants (at different s) shows high degree of repeatability and reproducibility of the method. Recovery (%) of 8-12% on cured rubber samples is attributed to different factors viz. o Homogenization in mixing o Loss of ingredients Fourth during level mixing / molding o Extraction However, it is within the acceptable range ( 8 12 %) for any analytical method This method can be used for qualitative as well as quantitative determination of anti-degradants present in tyre components 3

31 ACKNOWLEDGEMENT I would like to thank management and Organizers of Asia Rub Tech Expo 18 for allowing me to present our technical paper. 31

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