New processing agent in tire compounds.New processing agent in tire compounds Beginning in early 1980, the requirements for tire materials were becoming more and more specialized spe·cial·ize v. spe·cial·ized, spe·cial·iz·ing, spe·cial·iz·es v.intr. 1. To pursue a special activity, occupation, or field of study. 2. and diversified diversified (di·verˑ·s to achieve a specific dynamic property. One of the most important requirements is the better balance of fuel economy and safety. In the case of tire tread tread injury to the coronet of the horse's hoof by treading on it by the opposite hoof, or by another horse when they are being worked in a team. If the coronary matrix is injured there may be a subsequent crack or deformity. materials, these requirements are good wet traction Traction Definition Traction is the use of a pulling force to treat muscle and skeleton disorders. Purpose Traction is usually applied to the arms and legs, the neck, the backbone, or the pelvis. and low rolling resistance Rolling resistance, sometimes called rolling friction or rolling drag, is the resistance that occurs when an object such as a ball or tire rolls. It is caused by the deformation of the wheel or tire or the deformation of the ground. . It is well known that the materials showing good wet traction should have high tangent tangent, in mathematics. 1 In geometry, the tangent to a circle or sphere is a straight line that intersects the circle or sphere in one and only one point. delta at 0 [degree] C, while the compounds having low rolling resistance should have low tangent delta at 50-100 [degrees] C. These two properties are very critical because of the inherent viscoelastic Adj. 1. viscoelastic - having viscous as well as elastic properties natural philosophy, physics - the science of matter and energy and their interactions; "his favorite subject was physics" properties of polymers. In a wet skidding condition, the tread rubber performs at a relatively high frequency deformation deformation /de·for·ma·tion/ (de?for-ma´shun) 1. in dysmorphology, a type of structural defect characterized by the abnormal form or position of a body part, caused by a nondisruptive mechanical force. 2. at relatively low temperatures. On the other hand, in a rolling condition, the tread rubber experiences a relatively low frequency deformation at relatively high temperatures. A polymer with good wet skid/traction should be designed to have a relatively high glass transition temperature The glass transition temperature is the temperature below which the physical properties of amorphous materials vary in a manner similar to those of a solid phase (glassy state), and above which amorphous materials behave like liquids (rubbery state). . Thus, high glass polymer usually shows high hysteresis hysteresis (hĭs'tərē`sĭs), phenomenon in which the response of a physical system to an external influence depends not only on the present magnitude of that influence but also on the previous history of the system. and hence high fuel consumption. In emulsion emulsion: see colloid. emulsion Mixture of two or more liquids in which one is dispersed in the other as microscopic or ultramicroscopic droplets (see colloid). Emulsions are stabilized by agents (emulsifiers) that (e.g. SBR SBR - Spectral Band Replication or polybutadiene Polybutadiene is a synthetic rubber that has a high resistance to wear and is used especially in the manufacture of tires. It has also been used to coat or encapsulate electronic assemblies, offering extremely high electrical resistivity. , it has been known that good, wet skid/traction and low rolling resistance are contradictory to each other. For example, low glass transition high Cis polybutadiene rubber has very poor wet skid/traction, while it provides lower rolling resistance and good wear resistance. However, a high styrene sty·rene n. A colorless oily liquid from which polystyrenes, plastics, and synthetic rubber are produced. Also called vinylbenzene. content emulsion SBR provides high glass transition temperature resulting in high rolling resistance and good wet skid/traction. In that same period, Dunlop Dunlop is a surname, Scottish in origin. For people with family name Dunlop, see Dunlop (surname). Companies named Dunlop include
vinyl chloride a vinyl group to which an atom of chlorine is attached; the monomer which polymerizes to polyvinyl chloride; it is toxic group and fewer branches. The linear and high molecular weight SBR polymer provides lower hysteresis, good flexing and good wear resistance, while its processability is getting more difficult. The higher content of a vinyl group in solution SBR increases its glass transition temperature, which provides improved wet skid/traction. In industrial products, highly loaded compounds have been a problem for 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 fillers. Without a well mixed stock, especially in radiator hose Noun 1. radiator hose - a flexible hose between the radiator and the engine block cooling system, engine cooling system - equipment in a motor vehicle that cools the engine hosepipe, hose - a flexible pipe for conveying a liquid or gas , a crack frequently occurs in the early stages. The power transmission and v-belts have also broken due to poor mixing. Processing agents would assist to mix and process uniformly in industrial rubber products such as hoses, conveyor belts conveyor belt One of various devices that provide mechanized movement of material, as in a factory. Conveyor belts are used in industrial applications and also on large farms, in warehousing and freight-handling, and in movement of raw materials. , v-belts, power transmission belts and rubber sheets. In this article, Processing Agent 1109 has been introduced in lower oil tread, replacing oil with PA 1109, conventional tread and high modulus See modulo. tread compounds. Experiments with individual ingredients PA 1109 consists of organic esters esters (esˑ·terz), n.pl organic compounds synthesized from acids and alcohols, typically possessing fruity aromas. , paraffin wax paraffin wax Mixture of organic compounds traditionally derived from petroleum but also obtained synthetically. It usually consists of alkane hydrocarbons (also called paraffins) and is used for coating and sealing, for candles, and in floor waxes, lubricants, waterproofing and calcium carbonate calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. . The conventional tread compound, which contained 75/25 emulsion styrene butadiene butadiene (by  t'ədī`ēn), colorless, gaseous hydrocarbon. There are two structural isomers of butadiene; they differ in the location of the two carbon-carbon double bonds in the rubber (E-SBR)/ high Cis polybutadiene rubber
(Cis BR) and 55 phr of N-234 ISAF ISAF International Security Assistance Force (UN program)ISAF International Sailing Federation ISAF International Shark Attack File ISAF Israeli Air Force ISAF Information Security Awareness Forum (intermediate super 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. resistance furnance) carbon black, was utilized for the evaluation of the individual ingredients, commercial PA 1109 and a lab blend. The PA 1109, a lab blend, organic ester, calcium carbonate and wax were added to the conventional tread compound. A thiocarbamyl sulfenamide/2 (4-morpholinyl-mercapto) benzothiazole/ sulfur sulfur or sulphur (sŭl`fər), nonmetallic chemical element; symbol S; at. no. 16; at. wt. 32.06; m.p. 112.8°C; (rhombic), 119.0°C; (monoclinic), about 120°C; (amorphous); b.p. 444.674°C;; sp. gr. at 20°C;, 2. system was used to vulcanize vul·ca·nize tr.v. vul·ca·nized, vul·ca·niz·ing, vul·ca·niz·es To improve the strength, resiliency, and freedom from stickiness and odor of (rubber, for example) by combining with sulfur or other additives in the presence of heat the experimental tread compounds. With these experiments, conducted with an experimental passenger tire tread compound, one cure time and temperature was taken, 10 minutes at 177 [degrees] C. This higher temperature was utilized to simulate simulate - simulation the currently used curing temperature in the tire industry. The completely mixed compounds were measured for Mooney viscosity at 100 [degrees] C, Mooney scorch at 132 [degrees] C and curemeter at 177 [degrees] C, which had employed identical mixing procedure and cycle. All the cured samples were tested for unaged and aged stress/strain, and viscoelastic properties. Results and discussion The evaluation included five compounds. Compound A consisted of 3 phr of PA 1109, compound B contained 3 phr of a lab blend, compound C had 2 phr of organic esters, compound D consisted of 2 phr of calcium carbonate and compound E consisted of 2 phr of paraffin wax, which are shown in table 1. The 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. at 100 [degrees] C indicated that compounds A, B, C and E are approximately similar to each other except compound D, whose viscosity was higher than that of the other compounds. The three point rise time of the Mooney scorch at 132 [degrees] C for compound C was shorter than other compounds whose scorch time was not significantly different from each other. The 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 at room temperature and at 121 [degrees] C for both compound C and compound D was slightly higher than that of other compounds. The static modulus of compound D was much higher than that of the other compounds, however the static modulus of compound C was the same as compound D, measured at 121 [degrees] C. The static modulus for both compound C and compound D was much higher than that of the other compounds, tested at 121 [degrees] C. All other physical properties including 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. , Shore A hardness and tear strength (Die C) were not significantly different from each other, as shown in table 1. Table : Table - 1 unaged physical properties
A B C D E
E-SBR 1500 75 75 75 75 75
Cis BR 1203 25 25 25 25 25
N-234 black 55 55 55 55 55
Aromatic oil 15 15 15 15 15
PA 1109 3 - - - -
Blends - 3 - - -
Organic ester - - 2 - -
Calcium carbonate - - - 2 -
Paraffin wax - - - - 2
ML 1+4 at 100 [degrees] C 58 56 58 64 56
MS at 132 [degrees] C 28' 32' 24' 27' 31'
3 pt. rise time Cured at 177 [degrees] C 10' 10' 10' 10' 10' Tensile at RT 23.8 21.9 25.6 25.5 23.3 % Elongation 530 500 550 520 520 300% Modulus 10.9 10.2 10.7 12.0 10.8 Shore A hardness 68 63 68 69 67 Tear strength (Die C) 56.0 56.0 57.8 59.5 59.5 Tensile at 121 [degrees] C 9.4 8.9 9.9 10.9 9.6 % Elongation, 280 280 300 320 300 200% Modulus 5.2 5.4 6.2 6.0 5.3 Tear strength (Die C) 28.0 29.8 29.8 28.0 29.0 The shear shear: see strength of materials. Shear A straining action wherein applied forces produce a sliding or skewing type of deformation. loss modulus (G") and storage modulus (G") were measured by using a viscoelastic tester. Tangent delta (G"/G') and composite modulus [Mathematical Expression A group of characters or symbols representing a quantity or an operation. See arithmetic expression. Omitted] were computed from loss and storage modulus. The measurements were carried out with 1 through 12 Hertz hertz (hûrts) [for Heinrich R. Hertz], abbr. Hz, unit of frequency, equal to 1 cycle per second. The term is combined with metric prefixes to denote multiple units such as the kilohertz (1,000 Hz), megahertz (1,000,000 Hz), and gigahertz and at three different temperatures (50 [degrees] C, 75 [degrees] C and 100 [degrees] C. In table 2 and figures 2 and 3, only tangent delta and composite dynamic modulus Dynamic modulus is the ratio of stress to strain under vibratory conditions (calculated from data obtained from either free or forced vibration tests, in shear, compression, or elongation). It is a property of viscoelasticity materials. are shown with 10 Hertz, because the trends are the same with the other frequencies. The dynamic modulus of compound C is significantly higher than that of other compounds. Tangent delta of compound C is slightly higher than that of the others. All the cured samples were aged in an over for two weeks at 70 [degrees] C. Aged physical properties were measured for tensile strength, elongation, Shore A hardness, tear strength (Die C), modulus at room temperature and at 121 [degrees] C. No significant differences were observed among the five compounds (table 3). [Tabular tab·u·lar adj. 1. Having a plane surface; flat. 2. Organized as a table or list. 3. Calculated by means of a table. tabular resembling a table. Data Omitted] Experiments with lower oil tread It is well known that higher modulus tread which has a higher cornering coefficient coefficient /co·ef·fi·cient/ (ko?ah-fish´int) 1. an expression of the change or effect produced by variation in certain factors, or of the ratio between two different quantities. 2. provides a better handling radial radial /ra·di·al/ (ra´de-al) 1. pertaining to the radius of the arm or to the radial (lateral) aspect of the arm as opposed to the ulnar (medial) aspect; pertaining to a radius. 2. ply (mathematics, data) ply - 1. Of a node in a tree, the number of branches between that node and the root. 2. Of a tree, the maximum ply of any of its nodes. tire, and lower oil tread has better abrasion resistance or provides a better wear resistant tire. However, it is extremely difficult to mix and process lower oil tread compounds. In this experiment, six batches were mixed in a laboratory internal 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. with varying amounts (0 to 5 phr) of PA 1109. The lower oil tread compound contained 75/25 ESBR/Cis BR with 55 phr of N-234 ISAF carbon black and 10 phr 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. The same sulfur system as mentioned earlier was used to cure the lower oil tread compound. One cure time and temperature was taken, 10 minutes at 177 [degrees] C. The Mooney viscosity at 100 [degrees] C from the vulcanized rubber India rubber, vulcanized. - Knight. See also: Vulcanize and the unaged vulcanized vul·ca·nize tr.v. vul·ca·nized, vul·ca·niz·ing, vul·ca·niz·es To improve the strength, resiliency, and freedom from stickiness and odor of (rubber, for example) by combining with sulfur or other additives in the presence of heat samples were tested for tensile strength, elongation at break, modulus, tear strength and rheometer rhe·om·e·ter n. An instrument for measuring the flow of viscous liquids, such as blood. measurements. Results and discussion The Mooney viscosity at 100 [degrees] C was decreased with linear proportionality pro·por·tion·al adj. 1. Forming a relationship with other parts or quantities; being in proportion. 2. Properly related in size, degree, or other measurable characteristics; corresponding: as the same amount of PA 1109 was increased, which is shown in figure 1 and table 4. A three point rise time of the Mooney scorch at 132 [degrees] C was measured by using the Mooney viscometer with a small rotor rotor: see generator; motor, electric. . No differences in the Mooney scorch were observed among the six compounds. The 300% modulus of compound F, which contained 5 phr of PA 1109, was decreased significantly. The tensile strength, elongation at break, modulus, tear strength (Die C) and Shore A hardness are not significantly different from each other with 0 to 4 phr of PA 1109, which is shown in table 4. Table : Table 4 - unaged physical properties (lower oil tread
A B C D E F
E-SBR 1500 75 75 75 75 75 75
Cis BR 1203 25 25 25 25 25 25
N-234 black 55 55 55 55 55 55
Aromatic oil 10 10 10 10 10 10
PA 1109 - 1 2 3 4 5
ML 1+4 at 100 [degrees] C 69 67 66 64 62 60
MS at 132 [degrees] C, 20' 21' 21' 21' 21' 22'
3 pt. rise time Cured at 177 [degrees] C 10' 10' 10' 10' 10' 10' Tensile at RT, MPa 24.0 23.3 23.2 23.4 22.5 22.6 % Elongation 450 450 470 450 430 460 300% Modulus, MPa 13.7 13.6 13.2 13.1 13.2 12.1 Shore A hardness 68 65 67 68 68 65 Tear strength (Die C) KN/m 56.0 59.5 59.5 49.0 56.0 57.8 Tangent delta and composite dynamic modulus were measured with a viscoelastic tester. Tangent delta value was decreased as the PA 1109 was increased. However, with the addition of more than 4 phr of PA 1109, tangent delta began to increase (figure 2). The dynamic modulus for compounds A, B and C, which contained 0, 1 and 2 phr of PA 1109, were similar to each other, tested at 50 [degrees] C, 75 [degrees] C and 100 [degrees] C, respectively. However, with the addition of more than 3 phr of PA 1109, the dynamic modulus was reduced, which is shown in table 5 and figure 3. Table : Table 5 - rheometer measurement
A B C D E F
E-SBR 1500 75 75 75 75 75 75
Cis BR 1203 25 25 25 25 25 25
N-234 black 55 55 55 55 55 55
Aromatic oil 10 10 10 10 10 10
PA 1109 - 1 2 3 4 5
10Hz 10Hz 10Hz 10Hz 10Hz 10Hz
Tan TAN See tax anticipation note (TAN). [delta] (G"/G') at 50 [degrees] C .192 .182 .178 .193 .169 .181 G(*) (dyne/[cm.sub.2]) x 10.sub.7 6.17 6.15 6.12 5.64 4.81 5.39 Tan [delta] (G"/G') at 75 [degrees] C .172 .159 .159 .164 .144 .158 G(*) (dyne/[cm.sub.2]) x 10.sub.7 4.90 5.06 4.78 4.45 4.402 4.52 Tan [delta] (G"/G') at 100 [degrees] C .158 .145 .139 .144 .127 .149 G(*) (dyne/[cm.sub.2]) x 10.sub.7 4.33 4.55 4.06 3.90 3.49 3.97 Experiments with replacing oil with PA 1109 In this experiment, the lower oil tread compound was utilized by replacing oil with PA 1109 from 1 to 5 phr. Also, the lower oil tread compound contained 75/25 ESBR/Cis BR with 55 phr of N-234 ISAF carbon black. The same sulfur system was used. The cure time and temperature was also the same. The completely mixed five compounds were tested for viscosity at 100 [degrees] C, and the tensile strength, elongation at break, modulus, tear strength (Die C), and rheometer measurements were measured from the cured samples. Results and discussions The Mooney viscosity at 100 [degrees] C varied from 69 to 75 among all five batches. Due to different mixes, experimental errors have occurred. The physical properties showed no differences among them (table 6). However, in rheometer measurements, tangent delta (G"/G') with PA 1109 was much lower than that without PA 1109, except compound J, which might cause experimental errors (table 7 and figure 4). No significant differences in composite dynamic modulus were measured among all six batches, which are shown in table 7 and figure 5. Table : Table 6 - unaged physical properties (replacing oil with PA 1109)
G H I J K
E-SBR 1500 75 75 75 75 75
Cis BR 1203 25 25 25 25 25
N-234 black 55 55 55 55 55
Aromatic oil 9 8 7 6 5
PA 1109 1 2 3 4 5
ML 1+4 at 100 [degrees] C 73 67 75 68 70
MS at 132 [degrees] C 21' 21' 22' 23' 22'
3 pt. rise time Cured at 177 [degrees] C 10' 10' 10' 10' 10' Tensile at RT 25.1 24.0 25.2 22.6 24.6 % Elongation 430 450 430 430 440 300% Modulus 14.8 13.1 15.1 13.0 14.4 Shore A hardness 69 68 71 70 69 Tear strength (Die C) 56.0 54.3 63.0 56.0 52.5 Table : Table 7 - rheometer measurement
(*)A G H I J K
E-SBR 1500 75 75 75 75 75 75
Cis BR 1203 25 25 25 25 25 25
N-234 black 55 55 55 55 55 55
Aromatic oil 10 9 8 7 6 5
PA 1109 - 1 2 3 4 5
10Hz 10Hz 10Hz 10Hz 10Hz 10Hz
Tan [delta] (G"/G') at 50 [degrees] C .192 .191 .177 .155 .188 .161 G(*) (dyne/[cm.sub.2]) x 10.sup.7 6.17 6.09 5.73 5.84 6.16 6.02 Tan [delta] (G"/G') at 75 [degrees] C .172 .172 .163 .137 .168 .142 G(*) (dyne/[cm.sup.2]) x [10.sup.7] 4.90 5.11 4.74 4.80 4.83 5.00 Tan [delta] (G"/G') at 100 [degrees] C .158 .156 .147 .131 .155 .140 G(*) (dyne/[cm.sup.2]) x [10.sup.7] 4.33 4.51 4.14 4.14 4.08 4.25 (*) A from table 5 Experiments with conventional tread compound Studies were conducted with the basic recipe from a passenger tire tread compound. The conventional tread compound contained 75/25 E-SBR/Cis BR with 55 phr of N-234 ISAF carbon black and 20 phr of aromatic oil. Three different compounds were mixed in a laboratory size internal mixer and two cycle mixing procedures (masterbatch and final batch) were employed in preparing three compounds. Compound A does not contain a processing agent, compound B consists of 2 phr of PA 1109, compound C contains 3 phr of PA 1109 (table 8). The same vulcanization vulcanization (vŭl'kənəzā`shən), treatment of rubber to give it certain qualities, e.g., strength, elasticity, and resistance to solvents, and to render it impervious to moderate heat and cold. system was used, along with the same cure time and temperature. The Mooney sorch at 132 [degrees] C was measured from the completely mixed compounds. The cured samples were tested for unaged and aged physical properties, and rheometer measurements. Table : Table 8 - conventional tread compound
A B C
E-SBR 75 75 75
Cis BR 25 25 25
N-234 black 55 55 55
Oil 20 20 20
PA 1109 - 2 3
ML 1+4 at 100 [degrees] C 56 54 52
MS at 132 [degrees] C, 25' 25' 22'
3 pt. rise time Cure rate (min.) 4.6 4.5 4.4 Cured at 177 [degrees] C 10' 10' 10' Tensile, MPa at RT 23.4 23.2 23.1 Elongation, % 570 560 590 300% Modulus, MPa 9.4 9.1 8.7 Shore A hardness 61 65 65 Tear strength, KN/m 52.5 52.5 52.5 (Die C) Tensile, MPa at 121 [degrees] C 9.6 8.5 7.1 % Elongation 340 330 290 200% Modulus, MPa 4.3 3.9 4.3 Tear strength, KN/m 25.9 25.7 30.6 (Die C) Results and discussions The Mooney viscosity at 100 [degrees] C was decreased linearly as the amount of PA 1109 was increased in the conventional tread compound. The Mooney sorch and the cure rate at 132 [degrees] C were not significantly different from each other. Compound C, which contained 3 phr of processing agent, reduced 300% modulus at room temperature. Tensile strength and elongation at 121 [degrees] C was reduced slightly, however, the tear strength at 121 [degrees] C was increased slightly in compound C, compared with compound A and compound B, which are shown in table 8. The cured samples were aged in an oven for two weeks at 70 [degrees] C. Percent retention were not different from each other, measured at room temperature. Percent retention in tensile strength and elongation for compound C was better than that of compound A and compound B tested at 121 [degrees] C. Lower initial physical properties might contribute to these results for compound C, which are shown in table 9. The shear loss modulus and storage modulus were measured by rheometer. Table : Table - 9 conventional tread compound (% retention, aged two weeks at 70 [degrees] C
A B C
E-SBR 1500 75 75 75
Cis BR 25 25 25
N-234 black 55 55 55
Oil 20 20 20
PA 1109 - 2 3
Tensile, psi at RT 94.1 97.0 93.7
Elongation, % 77.2 80.4 78.0
300% Modulus 137.5 144.7 141.3
Shore A hardness 116.4 110.7 112.3
Tear strength (Die C) 103.3 96.7 91.0
Tensile at 121 [degrees] C 104.3 95.1 118.4
% Elongation, 82.3 78.8 96.6
200% Modulus 149.2 156.1 132.2
Tear strength (Die C) 87.8 81.6 74.3
Tangent delta and composite dynamic modulus were computed from loss and storage modulus. In compound B, tangent delta value was decreased significantly and a slight decrease in tangent delta for compound C was observed, compared with that of compound A which did not contain PA 1109, while composite dynamic modulus for both compound C and compound B was significantly increased. Good dispersion of polymers and blacks with PA 1109 will result. These results are shown in table 10 and figures 6 and 7. Table : Table 10 - conventional tread rheometer test results - frequency 10 Hz
A B C
E-SBR 1500 75 75 75
Cis BR 1203 25 25 25
N-234 black 55 55 55
Aromatic oil 20 20 20
PA 1109 - 2 3
Tan [delta] (G"/G') at RT .221 .185 .207
G(*) (dyne/[cm.sup.2]) x [10.sup.7] 7.22 7.68 8.82
Tan [delta] (G"/G') at 50 [degrees] C .204 .156 .175
G(*) (dyne/[cm.sup.2]) x [10.sup.7] 5.41 5.60 6.13
Tan [delta] (G"/G') at 75 [degrees] C .193 1.30 1.50
G(*) (dyne/[cm.sup.2]) x [10.sup.7] 4.40 4.61 5.02
Tan [delta] (G"/G') at 100 [degrees] C .176 .120 .134
G(*) (dyne/[cm.sup.2]) x [10.sup.7] 3.85 4.10 4.34
Experiments with high modulus tread In order to obtain a higher modulus tread compound, a tri-blend of solution styrene butadiene rubber, high vinyl content butadiene rubber and natural rubber was used with 55 phr of N-234 ISAF black, 20 phr of naphthenic oil and 0.5 phr of 4,4' dithiodimorpholine. The same system was used to vulcanize the high modulus tread compound. Compound A did not have either PA 1109 or 4,4' dithiodimorpholine, compound B consists of 4,4' dithiodimorpholine only and compound C contained both PA 1109 and 4,4' dithiodimorpholine. One cure time and temperature was taken, namely, 10 minutes at 177 [degrees] C. The Mooney viscosity at 100 [degrees] C and the Mooney scorch at 132 [degrees] C were measured from the uncured compounds, and other physical properties and rheometer measurements were made with the cured samples. Results and discussion Previously, in the introduction, it was mentioned that linear high molecular weight polymers, namely narrow distributed high molecular weight styrene butadiene rubber, provides lower hysteresis, which has resulted in lower rolling resistance. Also, high vinyl content in either styrene butadiene rubber or polybutadiene rubber increases the glass transition temperature as wet traction can be improved. The combination of these two polymers is very difficult in processing (mixing and extruding). Therefore, it is essential to have natural rubber for improving the process. The Mooney viscosity at 100 [degrees] C for compound C, which contained 3 phr of PA 1109, was reduced from 72 to 64. The Mooney scorch values at 132 [degrees] C were not significantly different from each other. However, the cure rate without 0.5 phr of 4,4' dithiodimorpholine is much faster than that with it. The 300% modulus significantly increased and the elongation at break was reduced because of the tight cure with 4,4' dithiodimorpholine. All other physical properties, including tensile strength and tear strength, were similar to each other. The cured ASTM ASTM abbr. American Society for Testing and Materials slabs were aged in an oven for two weeks at 70 [degrees] C. Percent retention in tensile strength for compound C is much higher than that of compound A and compound B. This result might come from PA 1109, which contains paraffin wax. In the rheometer measurements, tangent delta for compound C was much lower than that of compound A and compound B. Also, tangent delta value in compound B was lower than that of compound A because of the tight cure with 4,4' dithiodimorpholine. The dynamic modulus for compound C and compound B was much higher than that for compound A, as expected. Conclusion The combination of linear solution SBR and high vinyl content in either BR or SBR provides not only lower rolling resistance tread, but also improves wet skid/traction. These linear high molecular weight polymers would need a processing agent or blend with a highly branched polymer such as natural rubber to improve milling, mixing and extruding. The PA 1109, which consists of organic ester, paraffin wax and calcium carbonate, lowers the Mooney viscosity for improved processing, lowers hysteresis for lower rolling resistance tread, increases the dynamic modulus for improved handling tread and aids dispersion of carbon black for improved physical properties. References [1.] W.W. Klingbeil, S.W. Hong, R.N. Kienle and H.H. Witt, "Theoretical and experimental analysis of dual compound tread designs for reduced rolling resistance," presented at a meeting of the Rubber Division, ACS (Asynchronous Communications Server) See network access server. , Chicago, IL, October 5-7, 1982. [2.] John D. Ferry, "Viscoelastic properties of polymers," John Wiley John Wiley may refer to:
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 , 1960. [3.] Bill Kern Kern, river, 155 mi (249 km) long, rising in the S Sierra Nevada Mts., E Calif., and flowing south, then southwest to a reservoir in the extreme southern part of the San Joaquin valley. The river has Isabella Dam as its chief facility. and Shingo Futamura, "Solution SBR as tread rubber," presented at a meeting of the Rubber Division, ACS, Montreal, Quebec, May 26-29, 1987. [4.] Klaus Morche and H. Ehrend, "Tire compounds and process aids," presented at a meeting of the Rubber Division, ACS, Cleveland, Ohio "Cleveland" redirects here. For the Cleveland metropolitan area, see . For other uses, see Cleveland (disambiguation). Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County, the most populous county in the state. , October 6-9, 1987. PHOTO : Figure 1 - Mooney viscosity vs. PA 1109 PHOTO : Figure 2 - lower oil tread hysteresis vs. PA 1109 PHOTO : Figure 3 - lower oil tread composite dynamic modulus PHOTO : Figure 4 - replacing oil with PA 1109 - hysteresis vs. PA 1109 PHOTO : Figure 5 - replacing oil with PA 1109 - composite dynamic modulus PHOTO : Figure 6 - conventional tread hysteresis vs. PA 1109 PHOTO : Figure 7 - conventional tread - composite dynamic modulus |
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