The effect of peptizer on carbon black-rubber interaction in the internal mixer.Reinforcement, the improvement of the service life of rubber goods, is dependent on the behavior of the carbon black-elastomer interface. It is generally believed that the interaction between the filler fill·er 1 n. One that fills, as: a. Something added to augment weight or size or fill space. b. A composition, especially a semisolid that hardens on drying, used to fill pores, cracks, or holes in wood, plaster, and the matrix involves physical and chemical forces (ref. 1). The addition of carbon black significantly improves the physical and mechanical properties of elastomers, i.e., increasing modulus See modulo. , 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 , tear strength, fatigue resistance and wear resistance. A new model and theory have been proposed for the reinforcement of elastomers, based on the perspective of dynamic mechanics and mechanism of the reinforcement, using finite element See FEA. method (FEM FEM Female FEM Finite Element Method FEM Feminine FEM Finite Element Model FEM Fédération Européenne des Métallurgistes (European Metalworkers' Federation) FEM Faculdade de Engenharia Mecânica (Brasil) ) stress analysis (ref. 2). The reinforcement of elastomers by carbon black is governed by the morphology morphology In biology, the study of the size, shape, and structure of organisms in relation to some principle or generalization. Whereas anatomy describes the structure of organisms, morphology explains the shapes and arrangement of parts of organisms in terms of such of the black and its physical and chemical interactions with the polymer. In modern rubber-grade carbon blacks, strong bonding of the polymer to the carbon black surface is affected by several mechanisms, but surface chemical differences between blacks are relatively small, so that the dominant characteristic becomes the morphology (ref. 3). A higher bound rubber in cases of higher surface area carbon blacks was reported in the literature (ref. 4). Tan delta and resilience resilience (r  ·zilˑ·yens),n are mainly determined by the distance between aggregates (ref. 5). Carbon black reinforces ultimate properties of rubber by tear deviation. This can occur at the colloidal colloidal of the nature of a colloid. colloidal bath a bath containing gelatin, bran, starch or similar substances, to relieve skin irritation and pruritus. level, as the tear is forced to pass around carbon black aggregates, thus increasing the area of the torn surface. Colloidal tear deviation may be the cause of the increase in threshold tearing energy, which appears to be a small but significant component of reinforcement. In order to be effective, in this or other ultimate properties, the carbon black must not debond; i.e., failure must go through the rubber rather than through the debonded rubber-filler interface. Reinforcing carbon blacks do not debond (from diene Dienes are hydrocarbons which contain two double bonds. Dienes are intermediate between alkenes and polyenes. Classes Dienes can be divided into three classes:
Natural rubber requires controlled reduction in molecular weight, a process called mastication mastication /mas·ti·ca·tion/ (mas?ti-ka´shun) chewing; the biting and grinding of food. mastication (mas´tikā´sh , which is required for consistent mix quality. Reducing viscosity strictly by mechanical means has an inherent limitation. When the rubber is cold, the mixer mixer, either of two electronic devices in which two or more signals are combined. In the type of mixer used in radio receivers, radar receivers, and similar systems, a signal is translated upward or downward in frequency. provides high shear shear: see strength of materials. Shear A straining action wherein applied forces produce a sliding or skewing type of deformation. , and polymer breakdown occurs rapidly. However, mixing creates heat. As the mix warms, thermal softening softening /sof·ten·ing/ (sof´en-ing) malacia. softening a change of consistency, with loss of firmness or hardness. provides less shear, and the breakdown of molecular weight becomes slower. Chemical additives called peptizers have been developed to hasten has·ten v. has·tened, has·ten·ing, has·tens v.intr. To move or act swiftly. v.tr. 1. To cause to hurry. 2. this molecular cleavage cleavage, tendency of many minerals to split along definite smooth planar surfaces determined by their crystal structure. The directions of these surfaces are related to weaknesses in the atomic structure of the mineral and are always parallel to a possible crystal . As with all chemical reactions This is the 18th episode of television drama Men in Trees. It originally aired on June 25, 2007 on the TV2 network in New Zealand as a continuation of season 1. Recap Marin and Cash have a stew cook off, she admits his is better than hers. , the reaction of peptizers with NR occurs more rapidly as the temperature is increased. With the use of chemical peptizers, one generally sees a u-shaped curve of activity versus temperature (ref. 7). At the lowest temperature, the rate of breakdown is rapid because of high mechanical shear. As the temperature increases, the rate of breakdown declines to a minimum. At still higher temperatures, the chemical activity of the additive additive In foods, any of various chemical substances added to produce desirable effects. Additives include such substances as artificial or natural colourings and flavourings; stabilizers, emulsifiers, and thickeners; preservatives and humectants (moisture-retainers); and becomes the dominant effect and the rate of breakdown increases again. Internal mixers are very sensitive to changes in mixing time or rotor rotor: see generator; motor, electric. speed. High speed mixing reduces viscosity quite rapidly, but the batches may dump in a very sticky and non-uniform state. This problem may be partly due to inadequate dispersion dispersion, in chemistry dispersion, in chemistry, mixture in which fine particles of one substance are scattered throughout another substance. A dispersion is classed as a suspension, colloid, or solution. of the peptizer. It is recognized that breakdown at the more elevated temperatures is due to oxidative ox·i·da·tive adj. Of, relating to, or characterized by oxidation. oxidative, adj having the ability or property to oxidize. oxidative pertaining to or emanating from oxidation. scission scis·sion n. 1. A separation, division, or splitting, as in fission. 2. See cleavage. and that, in the lower temperature range and under the stresses set up during mastication, mechanical rupture rupture, in medicine: see hernia. of primary bonds is possible. The free radicals thus produced become stabilized sta·bi·lize v. sta·bi·lized, sta·bi·liz·ing, sta·bi·liz·es v.tr. 1. To make stable or steadfast. 2. by addition of oxygen. When mastication is carried out in the absence of oxygen, e.g., in an inert inert /in·ert/ (in-ert´) inactive. in·ert adj. 1. Sluggish in action or motion; lethargic. 2. atmosphere (either in an internal mixer or on a closed-in mill), little or no breakdown occurs. The general occurrence of mechanico-degradation when polymers undergo mastication or milling has been noted (ref. 8). Under these conditions, radicals resulting from mechanical shear recombine re·com·bine v. To undergo or cause genetic recombination; form new combinations. . The low-temperature breakdown of rubber is attributed to interaction of rubber radicals with oxygen to give oxygen-terminated fragments of lower molecular weight. Other radical acceptors can be expected to promote breakdown of rubber in an inert atmosphere and, moreover, do so in a manner capable of quantitative interpretation. Radical acceptors (ref. 9) that promote breakdown of rubber are not to be confused with chemical plasticizers plasticizers mostly triaryl phosphates, such as tricresyl, triphenyl phosphates, which are poisonous. See also triorthocresyl phosphate. (peptizers). The former are only effective under conditions of cold mastication and do not cause breakdown above 100 [degrees]C in the absence of oxygen. As the temperature reached in a mass of rubber during mastication is increased, the rubber becomes progressively softer, and the rate of mechanical rupture is correspondingly reduced. Hence, the breakdown efficiency in air or with radical acceptors under nitrogen falls with increasing temperature. A second type of breakdown due to conventional oxidative scission becomes apparent above 80 [degrees]C, and this increases rapidly with temperature. Interaction between carbon black and polymer starts during the mixing process. A primary agglomerate agglomerate Large, coarse, angular rock fragments associated with lava flow that are ejected during explosive volcanic eruptions. Although they may appear to resemble sedimentary conglomerates, agglomerates are igneous rocks that consist almost wholly of angular or rounded is formed, the composition of which is dependent upon the structure. Structure and specific activity determine incorporation time and further dispersion. During mixing, bound rubber is formed which is used as a measure of specific surface activity. In the final vulcanizate, the filler-polymer interaction is evident through reduced swelling in solvents like benzene benzene (bĕn`zēn, bĕnzēn`), colorless, flammable, toxic liquid with a pleasant aromatic odor. It boils at 80.1°C; and solidifies at 5.5°C;. Benzene is a hydrocarbon, with formula C6H6. , chloroform chloroform (klôr`əfôrm) or trichloromethane (trī'klôrōmĕth`ān), CHCl3 and cyclohexane cyclohexane (sī'kləhĕk`sān), C6H12, colorless liquid hydrocarbon. It is a cyclic alkane that melts at 6°C; and boils at 81°C;. It is nearly insoluble in water. (ref. 10). The higher [[gamma].sup.d.sub.s] (surface energy parameter) of carbon black causes strong filler-polymer interaction, which is reflected in a higher bound-rubber content of the compounds and higher moduli In theoretical physics, moduli are scalar fields whose different values are equally good (each one such scalar field is called a modulus). The reason is that the potential energy for moduli is constant, which can be guaranteed, for example, by supersymmetry (with of the vulcanizates at high elongation elongation, in astronomy, the angular distance between two points in the sky as measured from a third point. The elongation of a planet is usually measured as the angular distance from the sun to the planet as measured from the earth. (ref. 11). With regard to the effect of filler on the dynamic properties of a given polymer and cure system, filler networking, both its architecture and strength, is the main (although not only) parameter to govern the behavior of the filled rubber. From the ther modynamic and kinetic kinetic /ki·net·ic/ (ki-net´ik) pertaining to or producing motion. ki·net·ic adj. Of, relating to, or produced by motion. kinetic pertaining to or producing motion. points of view, filler network formation is especially related to filler-filler and polymer-filler, as well as polymer-polymer interactions (ref. 12). Factorial factorial For any whole number, the product of all the counting numbers up to and including itself. It is indicated with an exclamation point: 4! (read “four factorial”) is 1 × 2 × 3 × 4 = 24. designs are widely used in experiments involving several factors where it is necessary to study the joint effect of the factors on a response. By factorial design, it means that in each complete trial all possible combinations of the levels of the factors are investigated (refs. 13 and 14). The factors at two different levels are commonly used. Normally, it is assumed that the response is approximately linear over the range of the factor levels chosen. In a [2.sup.k] factorial design, it is easy to express the results of the experiment in terms of a regression model. This model is natural and intuitive. The two level factorial design experiments are carried out to ascertain the trend direction of the response. Rubber-carbon black interaction competes with rubber-peptizer reaction. This is a practical situation. Additionally, the state of natural rubber molecules is altered with the addition of aromatic aromatic /ar·o·mat·ic/ (ar?o-mat´ik) 1. having a spicy odor. 2. in chemistry, denoting a compound containing a ring system stabilized by a closed circle of conjugated double bonds or nonbonding electron pairs, e.g. oil and influenced by the solubility solubility Degree to which a substance dissolves in a solvent to make a solution (usually expressed as grams of solute per litre of solvent). Solubility of one fluid (liquid or gas) in another may be complete (totally miscible; e.g. match. In this state, it is interesting to study how the rubber would respond to the filler interaction and almost simultaneously with the peptizer. There seems to be no published information on this three-factor influence as of this date. In the present study, a two level, three factorial design is used to understand this situation through the assessment of cure and physico-mechanical characteristics of the rubber compositions. Experimental The selection of the formulations was done based on typical NR formulations. The standard design matrix and the compounding scheme are shown in tables 1 and 2. The test formulations and their mixing sequences are illustrated in table 3. An internal mixer (1.5 1) was used for both (master and final) stages of mixing. Final sheeting was done on an open 6" diameter and 13" width two-roll mill. Curing of the compounds was done in a 180 mt hydraulic press hydraulic press Machine consisting of a cylinder fitted with a piston (see piston and cylinder) that uses liquid under pressure to exert a compressive force upon a stationary anvil or baseplate. The liquid is forced into the cylinder by a pump. using hard chrome (jargon) chrome - (From automotive slang via wargaming) Showy features added to attract users but contributing little or nothing to the power of a system. "The 3D icons in Motif are just chrome, but they certainly are *pretty* chrome!" plated molds of 152 x 152 x 1.90 mm size as per ASTM ASTM abbr. American Society for Testing and Materials D 412. The following is the equipment used for characterizing compound properties: Mooney viscometer viscometer Instrument for measuring the viscosity (resistance to internal flow) of a fluid. In one type, the time taken for a given volume of fluid to flow through an opening is recorded. (MV 2000), rheometer rhe·om·e·ter n. An instrument for measuring the flow of viscous liquids, such as blood. (MDR MDR, n See multidrug resistance. MDR, n the abbreviation for minimum daily requirement, specifically the Minimum Daily Requirements for Specific Nutrients compiled by the United States Food and Drug Administration. 2000), hardness tester (IRHD IRHD International Rubber Hardness Degree ), tensile tensile, adj having a degree of elasticity; having the ability to be extended or stretched. tester (Z010), rebound resilience tester, dispersion rating tester (Dispergrader 1000 GT), specific gravity specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the two substances. tester and abrasion abrasion /abra·sion/ (ah-bra´zhun) 1. a rubbing or scraping off through unusual or abnormal action; see also planing. 2. a rubbed or scraped area on skin or mucous membrane. tester. Test procedures conform to Verb 1. conform to - satisfy a condition or restriction; "Does this paper meet the requirements for the degree?" fit, meet coordinate - be co-ordinated; "These activities coordinate well" the corresponding standards. The variables that were planned for study are: * Factor A - The peptizer content (0.1 and 0.3 phr); * Factor B - The amount of process oil (0 phr and 10 phr); and * Factor C. The peptizer's order of addition (with rubber and with carbon black). In order to obtain all vital information in the study, including interactions, and at the same time with a minimum required number of experiments, a two level, three factorial design of experiments was followed. In order to minimize experimental bias and to avoid wrongly attributing the variations in test data to the factor influence, the sequence of mixing was randomized ran·dom·ize tr.v. ran·dom·ized, ran·dom·iz·ing, ran·dom·iz·es To make random in arrangement, especially in order to control the variables in an experiment. and performed in replication, respectively. Results and discussion The eight mixes are shown as eight comers of a cuboid cuboid /cu·boid/ (kub´oid) 1. resembling a cube. 2. cuboid bone. cu·boid adj. Having the approximate shape of a cube. n. with the factors (peptizer, oil and order of addition) forming the sides (figure 1). The properties of the rubber vulcanizates are described in table 4. The structure of the basic response sheet is represented in table 5. The "average," "effect" and "regression coefficient Regression coefficient Term yielded by regression analysis that indicates the sensitivity of the dependent variable to a particular independent variable. See: Parameter. regression coefficient " values are derived and taken from the respective response sheets of properties. The approach to deduce de·duce tr.v. de·duced, de·duc·ing, de·duc·es 1. To reach (a conclusion) by reasoning. 2. To infer from a general principle; reason deductively: the regression equation Regression equation An equation that describes the average relationship between a dependent variable and a set of explanatory variables. (ref. 14) has been explained in detail in an earlier manuscript (ref. 15). The conformity of the deduced value with the observed value is described below. (Basic equation) Yi = yo + [a.sub.1][x.sub.1] + [a.sub.2][x.sub.2] + [a.sub.3][x.sub.3] + [a.sub.12] [x.sub.1][x.sub.2] + [a.sub.13] [x.sub.1][x.sub.3] + [a.sub.23][x.sub.2][x.sub.3] Regression equations deduced are: Mooney viscosity as observed parameter: [Y.sub.ML4] = 94.44 - 3.35 [x.sub.1] - 8.95 [x.sub.2] - 1.45 [x.sub.3] - 0.25 [x.sub.1] [x.sub.2] - 2.05 [x.sub.1] [x.sub.3] - 0.15 [x.sub.2] [x.sub.3] a) of higher range [Y.sub.6] = 94.44 -3.35(-1) -8.95(-1) -1.45(+1) -0.25(-1)(-1) -2.05 (-1)(+1) -0.15(-1)(+1) = 107.24 (vs. observed value = 108.2) b) of lower range [Y.sub.3] = 94.44 -3.35(+1) -8.95(+1) -1.45(-1) -0.25(+1)(+1) - 2.05(+1)(-1) - 0.15(+1) (-1) = 85.54 (vs. observed value = 84.4) MH as observed parameter: [Y.sub.MH] = 17.49 - 0.3 [x.sub.1] - 1.4 [x.sub.2] - 0.2 [x.sub.3] - 0.1 [x.sub.1] [x.sub.2] - 0.2 [x.sub.1] [x.sub.3] - 0.1 [x.sub.2] [x.sub.3] a) of higher range [Y.sub.6] = 17.49- 0.3 (-1)- 1.4 (-1)- 0.2 (+1)- 0.1 (-1) (-1)- 0.2 (-1) (+1) - 0.1 (-1) (+1) = 19.19 (vs. observed value = 19.15) b) of lower range [Y.sub.1] = 17.49- 0.3 (+1)- 1.4 (+1) - 0.2 (+1) - 0.1 (+1) (+1) - 0.2 (+1) (+1) - 0.1 (+l)(+1) = 15.19 (vs. observed value = 15.14) 300% modulus as observed parameter: [Y.sub.M300%] = 15.88 - 0.1 [x.sub.1] - 2.05 [x.sub.2] + 0.35 [x.sub.3] - 0.25 [x.sub.1] [x.sub.2] - 0.25 [x.sub.1] [x.sub.3] - 0.3 [x.sub.2][x.sub.3] a) of higher range [Y.sub.8] = 15.88 - 0.1 (+1)- 2.05 (-1) + 0.35 (+1)- 0.25 (+1) (-1) - 0.25 (+1)(+1) - 0.3 (-l)(+l) = 18.48 (vs. observed value = 18.57) b) of lower range [Y.sub.1] = 15.88 -0.1(+1) -2.05(+1) +0.35(+1) -0.25(+1)(+1) -0.25 (+1)(+1) - 0.3 (+1)(+1) = 13.28 (vs. observed value = 13.62) Tensile strength as observed parameter: [Y.sub.T] = 23.42 - 0.2 [x.sub.1] + 0.2 [x.sub.2] + 0.2 [x.sub.3] - 0.55 [x.sub.1][x.sub.2] + 0.1 [x.sub.1][x.sub.3] - 0.05 [x.sub.2] [x.sub.3] a) of higher range [Y.sub.5] = 23.42 - 0.2 (-1) + 0.2 (+1) + 0.2 (-1) -0.55 (-1)(+1) + 0.1 (-1)(-1) - 0.05 (+1)(-1) = 24.32 (vs. observed value = 24.44) b) of Iower range [Y.sub.3] = 23.42 -0.2 (+1) + 0.2 (+1) + 0.2 (-1) - 0.55 (+1)(+1) + 0.1 (+1)(-1) - 0.05 (+1)(-1) = 22.62 (vs. observed value = 22.46) Abrasion loss as observed parameter: [Y.sub.A] = 156.8 +4.5 [x.sub.1] + 17.5 [x.sub.2]- 0.2 [x.sub.3] + 4.8 [x.sub.1][x.sub.2] + 4.7 [x.sub.1][x.sub.3] + 2.7 [x.sub.2] [x.sub.3] a) of higher range [Y.sub.1] = 156.8 + 4.5 (+1) +17.5 (+1) - 0.2 (+1) + 4.8 (+1)(+1) + 4.7 (+1)(+1) + 2.7 (+1)(+1) = 190.6 (vs. observed value = 190) b) of lower range [Y.sub.6] = 156.8 + 4.5 (-1) + 17.5 (-1) - 0.2 (+1) + 4.8 (-1)(-1) + 4.7 (-1)(+1) + 2.7 (-1)(+l) = 132.0 (vs. observed value = 131.5) Hardness as observed parameter: [Y.sub.H]=71.4-0.6 [x.sub.1] - 1.9 [x.sub.2] + 0.1[x.sub.3] + 0.1 [x.sub.1][x.sub.2]-0.4 [x.sub.1] [x.sub.3] - 0.1 [x.sub.2] [x.sub.3] a) of higher value [Y.sub.6] = 71.4- 0.6 (-1) -1.9 (-1) + 0.1 (+1) + 0.1 (-1)(-1) - 0.4 (-1)(+1) - 0.1 (-1)(+1) = 74.6 (vs. observed value = 75) b) of lower range [Y.sub.3] = 71.4 - 0.6 (+1) - 1.9 (+1) + 0.1(-1) + 0.1 (+1)(+1) - 0.4 (+1)(-1) - 0.1 (+1) (-1) = 69.4 (vs. observed value = 69) Important findings (on interaction of order of addition, peptizer and oil) Effect of increase in peptizer on viscosity: * Addition of peptizer with carbon black, viscosity decreases by two to five units; and * addition of peptizer with rubber, viscosity decreases by 12 units. The increase in peptizer causes a viscosity reduction. This is more pronounced if it is added with the rubber. This observation indicates that the peptizer activity is stronger than the rubber-filler interaction. The schemes of the two competing reactions (ref. 16) are shown below. R--.+ XSH XSH Xml Editing Shell (peptizer) [right arrow] R--H + XS. (1) (Rubber chain radical) The peptizer activity (equation 1) is more prevalent than carbon black addition (equation 2). * Elongation at break: Highest elongation if peptizer is at 0.1 phr and with 10 phr oil; lowest elongation if peptizer is added with rubber and withholding Withholding Any tax that is taken directly out of an individual's wages or other income before he or she receives the funds. Notes: In other words, these funds are "withheld" from your wages. oil. Longer chains in a greater number in the plastic field would ensure higher elongation (ref. 17). At the same time, even with a given number of longer chains, if the plastic field is absent, the elongation suffers. * 5% modulus: Highest in case of 0.1 pht peptizer with rubber and without oil addition; lowest in case of 0.3 phr peptizer added with carbon black and with 10 phr oil. The observation that the highest initial modulus (5% mod.) occurs with a controlled peptization pep·tize tr.v. pep·tized, pep·tiz·ing, pep·tiz·es To disperse (a precipitate) to form a colloid. [Greek peptein, to digest; see pekw- of rubber in the absence of the oil concurs with general theory. At the same time, a higher peptizer (0.3 phr) going with carbon black and with 10 phr oil shows on one hand that such a procedure is detrimental to the modulus. On the other hand, a controlled peptization is also required, maybe to ensure a better alignment of rubber chains. * 300% modulus: Highest if peptizer at 0.3 phr is added with rubber and withholding any oil; lowest with oil at 10 phr, and 0.3 phr peptizer is added with rubber. A higher 300% modulus is possible only with higher peptizer going with rubber. It also requires a tighter network without oil. The 300% modulus, being a measure of strain-induced crystallization Crystallization The formation of a solid from a solution, melt, vapor, or a different solid phase. Crystallization from solution is an important industrial operation because of the large number of materials marketed as crystalline particles. , responds to higher degree of peptization. At the same time, the trend is reversed the moment the network is opened with oil addition. * Tensile strength: Highest in case of peptizer at 0.1 phr added with carbon black and with 10 phr oil; least in case of peptizer at 0.3 phr added with carbon black and with 10 phr oil. In the case of tensile strength, a moderate opening of the network (10 pht oil added) with a controlled molecular breakdown on peptization is advantageous. This is contrary to the trend in initial modulus (5% modulus) and implies that the trends in tensile strength and in initial modulus are not identical. * Abrasion resistance: Best if 0.1 phr peptizer added with rubber and without oil; poor if 0.3 phr peptizer added with rubber and with 10 phr oil. The vulcanizate offers the best abrasion resistance with a moderate reduction in molecular weight (peptization), and in a tighter network (without oil), in line with what was observed for the 5% initial modulus. The abrasion resistance is poor for a condition where 5% modulus is also low (0.3 phr peptizer + 10 phr oil). This is an important observation leading one to conclude that the conditions that favor the highest 5% modulus will also favor the best abrasion resistance (ref. 18). Conclusion These highlights, drawn from the experimental findings, lead to certain important conclusions regarding the role of factors other than carbon black in influencing vital control parameters Control parameters In a nonlinear dynamic system, the coefficient of the order parameter; the determinant of the influence of the order parameter on the total system. See: Order Parameter. of rubber vulcanizates. The control parameters mean the attributes of the rubber vulcanizates in terms of measurable properties that in many cases do not truly represent the behavior of the vulcanizates under the service conditions. However, it can be considered as effective under laboratory conditions. Therefore, one may end up optimizing the conditions, depending on the properties. For example, the findings suggest that the best abrasion resistance was obtained with peptizer at 0.1 phr, added with rubber, and withholding the process oil. And for high modulus peptizer at 0.3 phr, added with rubber and withholding the oil, is favored. For the tensile strength peptizer at 0.3 phr, added with the carbon black in the presence of 10 phr oil, was found to give the best result. The peptizer was found to have a greater influence on the rubber properties than the rubber-filler interaction. References (1.) Jean Le Bras and Eugene Papirer, "The filler-elastomer chemical link and the reinforcement of rubber, "Journal of Applied Polymer Science Polymer science or macromolecular science is the subfield of materials science concerned with polymers, primarily synthetic polymers such as plastics. The field of polymer science includes researchers in multiple disciplines including chemistry, physics, and engineering. , Volume 22, Issue 2, February 1978, pp. 525-531. (2.) Yoshihide Fukahori, "The mechanics and mechanism of the carbon black reinforcement of elastomers, '" Rubber Chemistry and Technology (2003), 76 (2), p. 548. (3.) Gerard Kraus, "Reinforcement of elastomers by carbon black," Rubber Chemistry and Technology (1978), 51(2), p. 297. (4.) Siegfried Wolff, Meng-Jiao Wang and Ewe-Hong Tan, "Filler-elastomer interactions. Part VII. Study on bound rubber," Rubber Chemistry and Technology (1993), 66 (2), p. 163. (5.) Meng-Jiao Wang, Siegfried Wolff and Ewe-Hong Tan, "Filler-elastomer interactions. Part VIII. The role of the distance between filler aggregates in the dynamic properties of filled vulcanizates," Rubber Chemistry and Technology (1993), 66(2),p. 178. (6.) A.I. Medalia, "Effect of carbon black on ultimate properties of rubber vulcanizates," Rubber Chemistry and Technology (1987), 60(1), p. 45. (7.) R.E Ohm, "Additives that affect mixing," chapter 6, The Mixing of Rubber, ed. by Richard E Grossman, Chapman & Hall, 1997. (8.) WE Watson, "Mechanico-chemical reactions of polymers, " abstract of Die Makromolekulare Chemic chem·ic adj. 1. Chemical. 2. Archaic Alchemic. n. Obsolete An alchemist. Adj. 1. , Volume 34, Issue 1, October 1959, pp. 240-252. (9.) GE Bloomfield, "Raw polymeric polymeric /poly·mer·ic/ (pol?i-mer´ik) exhibiting the characteristics of a polymer. pol·y·mer·ic adj. 1. Having the properties of a polymer. 2. materials," chapter 4, part A, 4.1, p. 87, Rubber Technology and Manufacture, Second Edition, ed by C.M. Blow and C. Hepburn, Butterworth, London, 1982. (10.) B.B. Boonstra, "Mixing of carbon black and polymer: Interaction and reinforcement," Journal of Applied Polymer Science, volume 11, issue 3, March 1967, pp. 389- 406. (11.) Siegfried Wolff and Meng-Jiao Wang, "Filler-elastomer interactions. Part IV. The effect of the surface energies of fillers on 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. reinforcement," Rubber Chemistry and Technology (1992), 65 (2), p. 329. (12.) Meng-Jiao Wang, "Effect of polymer-filler and filler-filler interactions on dynamic properties of filled vulcanizates," Rubber Chemistry and Technology (1998), 71 (3), p. 520. (13.) Douglas C. Montgomery, Design and Analysis of Experiments, Chapter 5, 5th edition, John Wiley John Wiley may refer to:
(14.) Robert E.H. Lochner and J.E. Matar, Designing for Quality: An introduction to the best of Taguchi and Western of Statistical Experimental Design, Chapman & Hall, 1990. (15.) B. Arun, V. Subrahmanian and V. Taneja, "Factorial design assisted experiment: Influence of carbon black, oil and anti-degradant in a NR/BR blend," Rubber World, Vol. 233 (2), November 2005, p. 28. (16.) W.F. Watson, "'Chemical interaction of fillers and rubbers during cold milling," chapter 8, p. 248, Reinforcement of Elastomers, edited by Gerard Kraus, 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 , 1965. (17.) Xuanying Zhang and Qiang Hu, Guoji LL "Oil-extended SBR SBR - Spectral Band Replication for use in agricultural tire treads," abstract of Huaxue Shijie (1985), 26 (3), 92-6. (18.) B.B. Boonstra, "Reinforcement by fillers," chapter 7, section 7.2, p. 271, Rubber Technology and Manufacture, Second Edition, ed. by C.M. Blow and C. Hepburn, Butterworth, London, 1982. V. Subrahmanian, B. Arun, V. Taneja and A. Nithya, Aditya Birla Fundamental Research Institute
Table 1--standard design matrix
Standard Factor Factor Factor
order no. A B C
1 1 1 1
2 -1 -1 -1
3 1 1 -1
4 1 -1 -1
5 -1 1 -1
6 -1 -1 1
7 -1 1 1
8 1 -1 1
Table 2--design matrix for the compounding study
Standard Factor A Factor B Factor C
order no. (peptizer) (oil) (pep. addition)
1 0.3 10 With rubber
2 0.1 0 With CB
3 0.3 10 With CB
4 0.3 0 With CB
5 0.1 10 With CB
6 0.1 0 With rubber
7 0.1 10 With rubber
8 0.3 0 With rubber
Table 3--test recipe details and mixing procedures
Ingredients Phr
Formulation no. F1 F2 F3 F4 F5 F6 F7 F8
1 NR STR 20 100 100 100 100 100 100 100 100
2 Accimel-PCTP 0.3 0.1 0.3 0.3 0.1 0.1 0.1 0.3
3 CB-N220 60 60 60 60 60 60 60 60
4 Zinc oxide 3 3 3 3 3 3 3 3
5 Stearic acid 1 1 1 1 1 1 1 1
6 Aromatic oil 10 - 10 - 10 - 10 -
7 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
8 CBS 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
Mixing condition
Start temp: 50[degrees]C, RPM 70, fill factor 80%
First stage: Order of addition
0 - 01:00 m:s Add rubber
01:01 - 02:00 1/2CB+ZnO+S.acid
02:01 - 03:00 Add remaining CB+oil
03:01 - 03:30 Sweep
03:40 Dump and sheet it out
Dump temperature: 125[degrees]C - 130[degrees]C
Maturation period: 2 hrs. at 25 [+ or -] 3[degrees]C
Second stage: Order of addition
0 - 00:30 m:s Warm masterbatch
00:31 - 01:30 Add curatives
01:31 - 01:40 Sweep
01:45 Dump and sheet it out
Cool at room temperature (25 [+ or -] 3[degrees]C)
Dump temperature: 95[degrees]C - 105[degrees]C
Table 4--rubber compound properties
SL Test
no. Physico-chemical properties UOM method
1 ML(1+4) @ Viscosity MU ASTM
100[degrees]C D1646
2 Scorch @ [t.sub.5] m:s D1646
125[degrees]C [t.sub.35] m:s
3 Rheological MH lb.in D6204
properties: ML lb.in
145[degrees]C [ts.sub.2] m:s
[t.sub.50] m:s
[t.sub.90] m:s
4 Hardness Durometer A D2240
IRHD D1415
5 Stress-strain 5% modulus MPa D412
properties: cured 50% modulus MPa
@ 145[degrees]C 100% modulus MPa
300% modulus MPa
Tensile strength MPa
Elong. brk %
6 Rebound DIN 53512, N = 5 D1054
7 Abrasion loss mg D5963
8 Specific gravity gm/cc
9 Dispersion rating "F" mode
SL
no. Physico-chemical properties F1 F2 F3
1 ML(1+4) @ Viscosity 78.3 105.7 84.4
100[degrees]C
2 Scorch @ [t.sub.5] 4.34 4.17 4.42
125[degrees]C [t.sub.35] 5.29 5.07 5.39
3 Rheological MH 15.14 18.99 16.20
properties: ML 2.73 3.60 3.12
145[degrees]C [ts.sub.2] 3.24 3.12 3.25
[t.sub.50] 4.44 4.45 4.41
[t.sub.90] 8.44 9.01 8.25
4 Hardness Durometer A 64 69 64
IRHD 69 73 69
5 Stress-strain 5% modulus 0.51 0.55 0.49
properties: cured 50% modulus 1.41 1.70 1.43
@ 145[degrees]C 100% modulus 2.59 3.11 2.62
300% modulus 13.62 16.54 13.79
Tensile strength 23.23 22.67 22.46
Elong. brk 479 393 468
6 Rebound DIN 53512, N = 5 36.5 41.2 37.1
7 Abrasion loss 190 148 177
8 Specific gravity 1.125 1.134 1.129
9 Dispersion rating "F" mode 6.8 7.0 7.2
SL
no. Physico-chemical properties F4 F5 F6
1 ML(1+4) @ Viscosity 103.7 89.7 108.2
100[degrees]C
2 Scorch @ [t.sub.5] 4.13 5.20 3.33
125[degrees]C [t.sub.35] 5.07 6.12 4.29
3 Rheological MH 18.91 16.52 19.15
properties: ML 3.51 3.25 3.71
145[degrees]C [ts.sub.2] 2.42 3.37 2.49
[t.sub.50] 4.13 4.53 4.17
[t.sub.90] 8.17 8.33 8.15
4 Hardness Durometer A 69 65 70
IRHD 73 70 75
5 Stress-strain 5% modulus 0.58 0.49 0.58
properties: cured 50% modulus 1.92 1.40 1.82
@ 145[degrees]C 100% modulus 3.73 2.58 3.56
300% modulus 18.02 13.79 18.55
Tensile strength 23.23 24.44 23.13
Elong. brk 383 487 370
6 Rebound DIN 53512, N = 5 39.5 35.8 39.6
7 Abrasion loss 140 170 131.5
8 Specific gravity 1.137 1.128 1.137
9 Dispersion rating "F" mode 6.1 6.5 6.0
SL
no. Physico-chemical properties F7 F8
1 ML(1+4) @ Viscosity 89.6 95.9
100[degrees]C
2 Scorch @ [t.sub.5] 4.36 3.00
125[degrees]C [t.sub.35] 5.34 3.49
3 Rheological MH 16.41 18.58
properties: ML 3.27 3.19
145[degrees]C [ts.sub.2] 3.24 2.14
[t.sub.50] 4.38 3.37
[t.sub.90] 8.14 7.22
4 Hardness Durometer A 65 68
IRHD 70 72
5 Stress-strain 5% modulus 0.52 0.56
properties: cured 50% modulus 1.45 1.89
@ 145[degrees]C 100% modulus 2.68 3.73
300% modulus 14.16 18.57
Tensile strength 24.31 23.84
Elong. brk 484 380
6 Rebound DIN 53512, N = 5 36.8 40.5
7 Abrasion loss 160 138
8 Specific gravity 1.127 1.138
9 Dispersion rating "F" mode 7.0 6.6
Table 5--basic response sheet structure
Standard Observed Peptizer Oil Order of
order no. value addition
A B C
1 -1 1 -1 1 -1
Property 0.3 0.1 10 0 With With
rubber CB
xxx
1 NE NE NE
2 NE NE NE
3 NE NE NE
4 NE NE NE
5 NE NE NE
6 NE NE NE
7 NE NE NE
8 NE NE NE
Total
No. of values 4 4 4 4 4 4
Standard Interaction
order no.
A * B A * C B * C
1 -1 1 -1 1 -1
1 NE NE NE
2 NE NE NE
3 NE NE NE
4 NE NE NE
5 NE NE NE
6 NE NE NE
7 NE NE NE
8 NE NE NE
Total
No. of values 4 4 4 4 4 4
Average (y0)
Effect (+1) - (-1)
Regression coeff. = effect/2
(NE = no entry)
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