Characterization of fatty acid modified reinforcing carbon black.Modification of carbon black filler for its reinforcement action has been a subject of study of many researchers. Grafting of selected oligomers and polymers onto the black surface, surface oxidation, use of different promoters and coupling agents, and reaction of various reactive compounds with carbon black are worth mentioning among the methods developed to-date. The researchers obtained varied outcomes with different systems. Donnet and co-workers (refs. 1-7) and later Ohkita (ref. 8) and Ysubokawa and co-workers (refs. 9-11) grafted oligomers and polymers on the carbon black surface without any significant improvement in the reinforcing activity. Harris and Wise (ref. 12) noted the use of a number of coupling agents and promoters for different elastomers. In many cases it was found to improve some properties at the cost of other properties. However, the toxic nature of these modifying agents has largely restricted their use for general purposes. Yamaguchi and co-workers (refs. 13 and 14) claimed improved dynamic properties in natural rubber (NR) and synthetic rubbers by using some non-nitroso coupling agents. Various silane silane or silicon hydride Any of a series of inorganic compounds of silicon and hydrogen with covalent bonds and the general chemical formula SinH(2n + 2). coupling agents were used for carbon black surface modification by Wolff and Goerl (refs. 15 and 16). The modified carbon blacks were used in rubber compounds to evaluate the changes in physico-mechanical properties of the elastomers. It was observed that only bis-(3-triethoxysilylpropyl) tetra sulphane (TESPT) treated carbon black showed some improvement in mechanical and dynamic properties in NR vulcanizates. Vidal and co-workers (ref. 17) used methanol and hexadecanol to modify the carbon black surface through esterification es·ter·i·fi·ca·tion n. A chemical reaction resulting in the formation of at least one ester product. es·ter  i·fied adj. . These modified blacks were used to evaluate their
reinforcing abilities in NR and styrene sty·renen. A colorless oily liquid from which polystyrenes, plastics, and synthetic rubber are produced. Also called vinylbenzene. butadiene rubber (SBR SBR - Spectral Band Replication ). It was observed that methanol modified black (N110) showed improved modulus, tensile strength tensile strength Ratio of the maximum load a material can support without fracture when being stretched to the original area of a cross section of the material. When stresses less than the tensile strength are removed, a material completely or partially returns to its and inferior elongation at break and abrasion loss as compared to untreated black, whereas hexadecanol modified black showed inferior properties, mentioned above. It was noted that esterification with alcohol has led to improvement in surface homogeneity and reduction in surface free energy which consequently has led to a decrease in filler-filler and polymer-filler interaction. Ghosh and co-workers (ref. 18) used long aliphatic aliphatic /al·i·phat·ic/ (al?i-fat´ik) pertaining to any member of one of the two major groups of organic compounds, those with a straight or branched chain structure. al·i·phat·ic adj. chain substituted phenol phenol (fē`nōl), C6H5OH, a colorless, crystalline solid that melts at about 41°C;, boils at 182°C;, and is soluble in ethanol and ether and somewhat soluble in water. (PP) to modify carbon black surface and reported reduced polymer-filler interaction and improved flex cracking resistance of natural rubber vulcanizates. In the present work, a simple method has been developed in the laboratory which is easy and provides a cost-effective technique for surface modification of carbon black using commercially available reagents and a process bi-product. The modified black is then characterized using several analytical tools. Experimental Reactants used were carbon black (N330, Hi Tech Carbon), dicumyl peroxide (DCP DCP - definitional constraint programming , E. Merck), process bi-product (PP; mixed long chain fatty acids, a proprietary item under patent application), N-1,3-dimethyl-butyl-N'-phenyl-paraphenylene-diamine (6PPD (1) (Parallel Presence Detect) The method used by earlier SIMM memory modules to communicate their capacity to the computer. A binary number coming from a parallel set of pins was read by the system, with each pin representing one bit. Contrast with SPD. , Bayer India). One hundred grams of previously dried (as per ASTM ASTM abbr. American Society for Testing and Materials D 3182-07) carbon black was mixed with 10g of PP in acetone acetone (ăs`ĭtōn), dimethyl ketone (dīmĕth`əl kē`tōn), or 2-propanone (prō`pənōn), CH3COCH3 in the presence of a requisite amount of DCP or 6PPD in a physical blending process at room temperature. The formulation of the mixture is shown in table 1. The mixture was air-dried for 12 hours and heated at a suitable temperature for 75 minutes. The treated black was then extracted with acetone for 72 hours and dried in vacuum at 50[degrees]C for 8-12 hours until constant weight. The extracted black was then subjected to a variety of testing to assess quantitatively and qualitatively the degree of modification. Results and discussions Estimation of the extent of surface attachment Gravimetric analysis gravimetric analysis n. The determination of the quantities of the constituents of a compound. for extent of attachment (ASTM E 1131) Carbon black was heated from 80-600[degrees]C under a constant purge of nitrogen (99.99% pure) in a Thermo Gravimetric Analyzer (TGA See TARGA. TGA - Targa Graphics Adaptor ), (TGA-7 from Perkin Elmer) and the weight loss was noted. The percent attachment is calculated from the weight loss of modified and control blacks, before and after acetone extraction. The results indicate the percent attachment of organic fatty acids with carbon black on modification. The data shown in table 2 are the average of two experiments at the same conditions. Fifteen percent attachment of PP to carbon black was achieved by heating at the specified temperature as indicated in CB 415 and CB 416. The presence of a small amount of amine amine (əmēn`, ăm`ēn): see under amino group. amine Any of a class of nitrogen-containing organic compounds derived, either in principle or in practice, from ammonia (NH3). (6PPD) did not help to increase the extent of attachment in CB 416. However, the bound PP content increased to 24% on heating in the presence of DCP. The above result shows the positive contribution of peroxide in forming some type of covalent co·va·lent adj. Of or relating to a chemical bond characterized by one or more pairs of shared electrons. linkage between fatty acid and carbon black. The presence of 6PPD has effectively deactivated the action of DCP, which is reflected in a substantial decrease of bound PP content in CB 414 as compared to CB 411; however, the extent of attachment was higher than when heated alone. The above results indicate that heating of the carbon black/PP mixture in the presence or absence of peroxide can be regarded as an effective technique for attachment of PP on the carbon black surface. [FIGURE 1 OMITTED] [FIGURE 2 OMITTED] Analysis by electron spectroscopy Electron spectroscopy is an analytical technique to study the electronic structure and its dynamics in atoms and molecules. In general an excitation source such as x-rays, electrons, or synchrotron radiation will eject an electron from an inner-shell orbital of an atom. for chemical analysis The XPS (1) See XML Paper Specification. (2) A brand name for certain models of Inspiron laptops from Dell. (or ESCA ESCA Electron Spectroscopy for Chemical Analysis ESCA Escaflowne (anime series) ESCA European Speech Communication Association ESCA Escuela Superior de Comercio y Administración (México) ) analysis was carried out using a VG make Escalab MK200X system. Carbon black samples were pressed on indium foil for analysis. The analysis chamber was kept under vacuum (1.2 x [10.sup.-9] mbar) during the analysis. During the experiment, the survey spectrum was restricted to 0-600ev. Figure 1 shows a typical survey spectrum for CB 414. Since the sample was placed in indium foil, the characteristic spectra of indium have appeared along with Cls, Ols and Nls. Figure 2 shows the ESCA peaks for Cls of the control, and modified blacks. The Cls peak of CB 411 and CB 414 are shifted to the higher binding energy relative to the control. This positive shift was due to attachment of polar carboxylic car·box·yl n. The univalent radical, COOH, the functional group characteristic of all organic acids. [carb(o)- + ox(y)- + -yl. groups. The shift was more for CB 414 relative to CB 411 due to the presence of additional amine groups (from 6PPD). The Cls shift of CB 415 and CB 416 was higher than the control, but less than CB 411 and CB 414. This is attributed to a lower extent of attachment of fatty acid groups on the carbon black surface. A relatively broad Ols peak for CB 411 and CB 414 as compared to the control, as observed in figure 3, indicated the presence of groups such as carbonyl carbonyl /car·bon·yl/ (kahr´bah-nil) the bivalent organic radical, C:O, characteristic of aldehydes, ketones, carboxylic acid, and esters. car·bon·yl n. The bivalent radical CO. , hydroxyl hydroxyl /hy·drox·yl/ (hi-drok´sil) the univalent radical OH. hy·drox·yl n. The univalent radical or group OH, a characteristic component of bases, certain acids, phenols, alcohols, carboxylic , carboxylic, ether, etc. (ref. 19). The atomic ratios of the Control, CB 411, CB 414, CB 415 and CB 416 are shown in table 3. The ESCA study thus confirmed the attachment of carboxylic groups in CB 411, and attachment of carboxylic and amine groups in CB 414. Atomic ratio calculations, shown in table 3, further support the findings of TGA for the extent of surface attachment. Estimation of the homogeneity of surface attachment through energy dispersive dispersive /dis·per·sive/ (-per´siv) 1. tending to become dispersed. 2. promoting dispersion. x-ray spectroscopy x-ray spectroscopy n. X-ray spectrometry. (EDX EDX Energy Dispersive X-Ray (Spectroscopy) EDX Electronic Data Exchange EDX Extended Data Register EDX Event-Driven Executive (IBM Series/1 OS) EDX Event-Based Data Exchange (UPNet) ) Elemental mapping through EDX was carried out with the help of a Quantax 200 with a X-flash LN2 free EDS (Electronic Data Systems, Plano, TX, www.eds.com) Founded in 1962 by H. Ross Perot (independent candidate for the President of the U.S. in 1992), EDS is the largest outsourcing and data processing services organization in the country. detector from Bruker, Germany. The oxygen mapping is shown in figures 4a to 4e. [FIGURE 3 OMITTED] It is observed that the oxygen concentration in the modified blacks follows the order of CB 411 > CB 414 > CB 415 ~ CB 416 > control. This matched the findings of thermogravimetric analysis Thermogravimetric Analysis or TGA is a type of testing that is performed on samples to determine changes in weight in relation to change in temperature. Such analysis relies on a high degree of precision in three measurements: weight, temperature, and temperature change. shown in table 2. The absence of localized concentration of oxygenated groups in oxygen x-ray mapping (in figure 3) confirms the uniformity of surface attachment achieved in the carbon black surface modification process. Adsorption adsorption, adhesion of the molecules of liquids, gases, and dissolved substances to the surfaces of solids, as opposed to absorption, in which the molecules actually enter the absorbing medium (see adhesion and cohesion). studies BET nitrogen adsorption The surface area determined by the BET adsorption isotherm isotherm, line drawn on a map of a particular region of the earth's surface connecting points of equal temperature; each point reflects one temperature reading or an average of several readings over a period of time. method is shown in table 4, which is the average of two experiments at the same conditions. The surface area decreased from 70.32 for the control black to 67.81 for CB 411. However, for the other modified blacks (CB 414, CB 415 and CB 416) the surface areas are comparable. This indicated slight surface oxidation in CB 411 due to the action of peroxide, resulting in reduction of surface area. However, the presence of amine in CB 414 seemed to have interacted with peroxide, reducing the effect of peroxide on surface oxidation. This has resulted in a comparable BET area of CB 414 with the control. CB 415 and CB 416 did not show any reduction in surface area with respect to control. [FIGURE 4a OMITTED] [FIGURE 4b OMITTED] [FIGURE 4c OMITTED] Iodine adsorption The surface area measured by iodine adsorption is shown in table 4. It was noted (ref. 20) that the impurities present, oxygen-containing groups and chemical groups formed after surface oxidation react with potassium iodide potassium iodide n. A white crystalline compound used as a source of iodine to treat thyrotoxic crisis and to prevent thyroid cancer in the event of overexposure to nuclear radiation. It is also used as an expectorant and antifungal. in the test solution, resulting in release of free iodine and lower surface area. In the present study, significant reduction of iodine number of modified blacks as compared to control black was observed, which is attributed to surface attachments. In CB 414 and CB 416, the iodine number was slightly higher than those of CB 411 and CB 415, respectively, which may be due to deactivation de·ac·ti·vate tr.v. de·ac·ti·vat·ed, de·ac·ti·vat·ing, de·ac·ti·vates 1. To render inactive or ineffective. 2. To inhibit, block, or disrupt the action of (an enzyme or other biological agent). 3. of surface oxygen groups in the presence of an amine group. [FIGURE 4d OMITTED] [FIGURE 4e OMITTED] The difference between BET surface area and iodine number is regarded as an estimation of porosity (ref. 21). However, on comparing the data from table 4 (difference of iodine number and BET surface area) to that of micro pore area shown in table 5, no correlation could be established. Surface area and pore volume analysis Surface area is an important property for prediction of rubber reinforcement characteristics. Carbon black with small particle size Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. has more external surface available for rubber interaction. Any internal surface of a carbon black inaccessible to rubber molecules has no part in rubber reinforcement (ref. 22). It has long been recognized that carbon black particles may have surfaces of a porous nature (ref. 23). The internal area of carbon black is composed primarily of pores with less than 20[Angstrom angstrom (ăng`strəm), abbr. Å, unit of length equal to 10−10 meter (0.0000000001 meter); it is used to measure the wavelengths of visible light and of other forms of electromagnetic radiation, such as ultraviolet ] diameter, commonly referred as micro pores (ref. 24). It was found that slit-like pores are most likely to occur in carbon blacks, caused by a deficiency of a discrete number of layer planes each of a thickness of about 3.5[Angstrom] (ref. 25). It was shown by Aboytes and co-workers (ref. 26) that all pores less than 20[Angstrom] width were inaccessible to SBR with molecular weight 300,000, and the surface in the pores of carbon black generally does not participate in reinforcing elastomers. The data shown in table 5 indicate that the surface modification of carbon black in the presence of peroxide has effectively covered up some of the micro pores, which further confirmed surface attachment of fatty acid chains by carbon black. Micro pore area was reduced considerably in CB 411 and CB 414 as compared to the control, indicating substantial coverage of pores by PP in the presence of peroxide. The presence of 6PPD has also contributed positively in pore area coverage. This is seen in the micro pore area in CB 414 and CB 416 as compared to CB 411 and CB 415, respectively. Analytical properties of modified carbon black Some of the physical properties of the control and modified carbon blacks are shown in table 6, which is the average of two experiments at the same conditions. Tinting strength increases with diminishing particle size. Medalia and Richards (ref. 27), Hess and Chirico (ref. 28) have reported a strong inverse relationship A inverse or negative relationship is a mathematical relationship in which one variable decreases as another increases. For example, there is an inverse relationship between education and unemployment — that is, as education increases, the rate of unemployment between tinting strength and aggregate size as measured by TEM/AIA. McDonald and Hess (ref. 29) showed an inverse relationship between tint and carbon black aggregate width (mean cord). These results indicate that tinting strength tends to increase with the breakdown of the carbon black aggregate and decrease with micro agglomeration ag·glom·er·a·tion n. 1. The act or process of gathering into a mass. 2. A confused or jumbled mass: . In addition, tint strength also decreases with broader particle size distribution The particle size distribution[1] ("PSD") of a powder, or granular material, or particles dispersed in fluid, is a list of values or a mathematical function that defines the relative amounts of particles present, sorted according to size. . Table 6 shows substantial reduction in the tint strength of the modified carbon blacks as compared to the control. Strong polar interactions of surface attached carboxylic acid carboxylic acid: see carboxyl group. carboxylic acid Any organic compound with the general chemical formula −COOH in which a carbon (C) atom is bonded to an oxygen (O) atom by a double bond to make a carbonyl group (−C=O; see groups has resulted in micro-agglomeration and subsequent reduction in tint strength of the modified blacks as compared to the control. The DBP DBP Diastolic Blood Pressure DBP Development Bank of the Philippines DBP Database Project (Visual Studio File Extension) DBP DNA Binding Protein DBP Disinfection Byproduct DBP Deutsche Bundespost absorption test is one of the most widely used methods for measuring the level of aggregate absorptivity in carbon black. A slight reduction of DBP values of the modified blacks indicated: a) attachment of fatty acid groups on the black surface leading to reduction of DBP intake volume and/ or b) possible breakdown of aggregate structure during physical blending of fatty acids with the black. However, the reason for DBP reduction of modified blacks was not studied further. The pH measurement of the aqueous slurry of the modified carbon black was lower than that of the control. This is attributed to an increase in PP content on the surface of carbon black after modification. The presence of amine group is expected to interact with acidic groups on the carbon black surface, resulting in an increase in the pH of the medium, which is actually seen (table 6). Surface topography analysis by scanning electron microscope scan·ning electron microscope n. Abbr. SEM An electron microscope that forms a three-dimensional image on a cathode-ray tube by moving a beam of focused electrons across an object and reading both the electrons scattered by the object and Analysis of surface topography using secondary electron secondary electron n. An electron produced in secondary emission. secondary electron An electron produced by secondary emission. mode Surface topography of the modified carbon blacks was analyzed using an XL-30 ESEM ESEM Environmental Scanning Electron Microscope ESEM International Symposium on Empirical Software Engineering and Measurement ESEM Experiment of Space Environment with Materials ESEM Ethernet Service Expansion Module (from Philips, Netherlands) using an E-T (Evahert Thornley) detector for secondary electron (SE) mode and using a semi-conductor detector for back scattered electron (BSE See Bombay Stock Exchange. BSE See Boston Stock Exchange (BSE). ) mode. Figure 5a shows the scanning electron micrographs of control and surface modified blacks in secondary electron emission (SE) mode at 1,000x magnification. The following observations were made from the SEM micrographs: * Surface topography of the modified blacks was different from that of the control black. More agglomerated agglomerated of particles, compacted together into a mass. agglomerated feeds particulated feeds compacted or extruded into pellets and similar forms. structure was observed in modified blacks as compared to control black. Possibly, the agglomeration was due to enhanced interaction of polar -COOH groups and other oxygen-containing groups formed during heat treatment in the presence of peroxide. * Qualitatively, the extent of carbon black agglomeration is in the following order: CB 411 > CB 414 > CB 415 [congruent to] CB 416 > control, which matched well with the findings of TGA analysis shown in table 2. Analysis of surface using backscatter backscatter in radiology, radiation deflected by scattering processes at angles greater than 90 degrees to the original direction of the beam of radiation. Important in radiotherapy when estimating surface exposure dose. electron emission (BSE) technique The number of backscatter electrons produced increases with increasing atomic number atomic number, often represented by the symbol Z, the number of protons in the nucleus of an atom, as well as the number of electrons in the neutral atom. Atoms with the same atomic number make up a chemical element. of the specimen. For this reason, a sample that is composed of two or more different elements, differing in atomic number, would produce an image that shows differential contrast of the elements in spite of uniform topology. Elements with higher atomic number would produce more backscattered electrons and would therefore appear brighter than neighboring elements. Figure 5b shows the backscatter electron micrographs of the control and modified blacks at 1,000x magnification. From the figure, it appears that the oxygen atom concentration (of the -COOH group and other oxygen-containing groups formed during heat treatment) is in the following order: CB 411 > CB 414 > CB 415 [approximately equal to] CB 416 > control. This further supported the findings of TGA and ESCA studies, as shown in tables 2 and 3. Conclusion The extent of surface modification was determined by TGA. XPS studies confirmed the presence of carboxylic groups on the modified carbon black surface. Atomic ratio calculations further support the findings of TGA. Oxygen x-ray mapping through EDX analysis confirmed the homogeneity of PP attachment on the carbon black surface achieved through the modification process. Attachment of polar groups on the surface of modified blacks has resulted in extensive agglomeration as compared to the control black. This was confirmed by SEM studies on the carbon blacks. The back scattered electron studies further confirmed the attachment of PP on the surface of modified blacks. The presence of peroxide enhanced the extent of attachment. The presence of a small amount of amine (6PPD) did not help to increase the extent of attachment. [FIGURE 5a OMITTED] [FIGURE 5b OMITTED] With surface attachment, modified blacks turned more acidic and showed lower analytical properties like tinting strength, DBP absorption, iodine number, etc., conventionally used to characterize carbon black. Modified blacks showed slightly lower external surface area than the control black. The micro pore area of the modified blacks was lower than the control black. This showed that during surface attachment some of the micro pores were covered by PP. References (1.) Donnet, J.B., Henrich, L.G. and Riess, G., (1962) Rev. Gen. Caout. Plast., 39, 583. (2.) Donnet, J.B., Geldreich, L. Henrich, G. and Riess, G., (1964) Rev. Gen. Caout. Plast., 41, 513. (3.) Donnet, J.B. and Henrich. G., (1960) J. Polym. Sci, 46, 277. (4.) Donnet, J.B., Peter, G. and Riess, G., (1969) J. Polym. Sci., 22, 645. (5.) Donner, J.B., Vidal, A., Riess, G. and Geldreich, L., (1970) Rev. Gen. Caout. Plast., 47, 1,289. (6.) Donnet, J.B., Riess, G. and Majowski, G., (1971) Eur. Polym. J., 7, 1,065. (7.) Papirer, E, Donnet, J.B., Riess, G. and Angew, N. Van Tao., (1971) Makromol. Chem. 19, 65. (8.) Ohkita, K., Kitahara, N. and Yamazaki, H., (1965) Nippon Gomu Kyokaishi, 38, 13. (9.) Tsubokawa, N., Jain, T., Yamada, A. and Sone, Y., (1986), Polym. Bull., 16, 249. (10.) Tsubokawa, N., Kuroda, A. and Sone, Y., (1989) J. Polym. Sci. Polym. Chem., 27, 1,701. (11.) Tsubokawa, N., Fujiki, K., and Sone, Y., (1986)J. Polym. Sci. Polym. Chem., 24, 191. (12.) Harris, J.O. and Wise, R.W., (1965) Reinforcement of Elastomers, G. Kraus, (Ed)., Interscience, New York New York, state, United States New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of , chap. 9. (13.) Yamaguchi, T., Kurimoto, I., Ohashi, K. and Okita, T., (1989) Kautsch. Gummi Kunstst., 42, 403. (14.) Yamaguchi, T., Kurimoto, I., Nagasaki, H. and Okita, T., (1989) Rubber World 199 (5), 30. (15.) Wolff, S. and Goerl, U., (1991) Kautsch Gummi Kunstst. 44, 941. (16.) Wolff, S. and Goerl, U., (1992) Eur. Pat. Appl. EP 468140. (17.) Vidal, A., Hao hao n. pl. hao See Table at currency. [Vietnamese hào.] Noun 1. , S.Z and Donnet, J.B., (1991) Kautsch Gummi Kunstst. 44, 419. (18.) Ghosh, A.K., Maiti, S., Adhikary, B., Ray, G.S. and Mustafi, S.K., (1997), J. Appl. Polym. Sci. 66, 683. (19.) Bertrand, P. and Weng, L. T., (1999) Rubber Chem. Technol., 72, 384. (20.) Hess, W.M. and Herd, C.R., (1993), "Carbon black science and technology," J.B. Donnet, R.C. Bansal and M.J. Wang (Ed.), Marcel Dekker, chapter 3, p. 119. (21.) Shanmughraj, A.M. and Bhowmick, A.K., (2002) Rubber Chem. Technol., 75, 605. (22.) Aboytes, P. and Voet, A., (1970) Rubber Chem. Technol., 43, 464. (23.) Dannenberg, E.M., and Boonstra, B.B., (1955) Rubber Chem. Technol., 28, 878. (24.) Lowell, S. and Shields, J.E. (1991) Powder Surface Area and Porosity, Chapman and Hall Chapman and Hall was a British publishing house, founded in the first half of the 19th century by Edward Chapman and William Hall. Upon Hall's death in 1847, Chapman's cousin Frederic Chapman became partner in the company, of which he became sole manager upon the retirement of , New York, p. 72. (25.) Voet, A., Lamond, T.G. and Sweigart, D., (1968) Carbon 6, 707. (26.) Aboytes, P. and Voet, A., (1970) Rubber Chem. Technol. 43, 464. (27.) Medalia, A.I. and Rechards, L.W., (1972) J. Coll. Interf. Sci., 40, 233. (28.) Hess, W.M. and Chirico, V.E., (1970-71) Akron Rubber Group symposia. (29.) Macdonald, G.C. and Hess, W.M., (1977) Rubber Chem. Technol., 50, 842. by Abhijit Adhikary, L&T e-Engineering Solution; Pranab Kumar Sengupta, University of Calcutta Formally established on the 24 January 1857, the University of Calcutta (also known as Calcutta University) (Bengali: কলকাতা বিশ্ববিদ্যালয়), located in ; and Rabindra Mukhopadhyay, Hari Shankar Singhania Elastomer elastomer (ĭlăs`təmər), substance having to some extent the elastic properties of natural rubber. The term is sometimes used technically to distinguish synthetic rubbers and rubberlike plastics from natural rubber. & Tyre Research Institute (abhijit.adhikary@ltees.com)
Table 1-composition of carbon black
for modification
CB (N330) CB PP DCP 6PPD
designation (g) (g) (g) (g)
Control 100
CB 411 100 10 0.8 --
CB 414 100 10 0.8 0.8
CB 415 100 10 -- --
CB 416 100 10 -- 0.8
Table 2-estimation of surface attachment in modified carbon black
CB (N330) Bound PP on
designation CB (9/.) by TGA
Control --
CB 411 24
CB 414 19
CB 415 15
CB 416 15
Table 3-atomic ratio analysis by ESCA
Sample Atomic ratio
identification (O/C) (%)
Control 2.04
CB 411 7.52
CB 414 6.38
CB 415 6.91
CB 416 6.56
Table 4-adsorption characteristics of surface modified carbon blacks
Black Multipoint Iodine Difference between
designation BET NSA, no. BET surface area and
[m.sup.2]/g (mg/g) [I.sub.2] number
Control 70.32 80.1 (-)9.78
CB 411 67.81 51.1 16.71
CB 414 70.97 53.4 17.57
CB 415 70.44 53.3 17.14
CB 416 69.93 54.1 15.83
Table 5-surface area and. pore volume analysis
Black Multipoint External Micropore area
BET NSA, surface area, [m.sup.2]/g
[m.sup.2]/g STSA [m.sup.2]/g
Control 70.32 62.96 7.36
CB 411 67.81 64.23 3.57
CB 414 70.97 68.71 2.26
CB 415 70.44 64.24 6.20
CB 416 69.93 64.05 5.88
Table 6-characteristic analytical properties
of modified carbon black
Black Tint (% ITRB) DBPA (cc/100g) pH
Control 103.8 101.5 6.48
CB 411 81.5 93.2 4.65
CB 414 76.5 91.4 4.82
CB 415 78.5 90.6 4.67
CB 416 78.5 90.1 4.8
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