Effect of Functionalization of Carbon Black on Rubber Properties

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12.0 10.0 8.0 6.0 4.0 2.0 0.0 Strain, % 0.0 Strain, % 0.1 1 10 100 0.1 1 10 100 Figure 8. Strain dependence <strong>of</strong> G' at 70°C and 10 Hz for OESSBR/BR and NR compounds filled with a variety <strong>of</strong> fillers strain dependence <strong>of</strong> the elastic modulus, G’(Figure 8). For filled rubber, the elastic modulus decreases with strain amplitude, which has been termed the “Payne effect”. 7 This effect is generally used as a measure <strong>of</strong> filler networking, controlled mainly by filler-filler interaction. 8 Although from the chemical composition point <strong>of</strong> view, both CSDPF 2000 and 4000 are between carbon black and silica, what is actually observed here is that the two new fillers give the lowest Payne effect. This unique behavior <strong>of</strong> the two new materials is readily explained by the low filler-filler interaction due to their hybrid surfaces. It has been established that from the point <strong>of</strong> view <strong>of</strong> surface energies, interaction between unlike surfaces is lower than that between the same category surfaces. 1 G', MPa Silica N234 CRX4210 CRX4210/TESPT 2.7 phr OESSBR/BR 70/30, Filler: equal volume 70°C, 10 Hz Due to the higher surface activity on the surface <strong>of</strong> carbon domains and lower filler-filler interaction, it is evident that these fillers will require significantly lower silane coupling agent compared to silica. Application <strong>of</strong> CSDPF 2000 and CSDPF 4000 in Tire Tread Compounds Following the discussion on the filler parameters that control the tire performance, the higher polymer-filler interaction and lower filler-filler interaction <strong>of</strong> CSDPF 2000 and 4000 will allow a better compromise between abrasion resistance and dynamic hysteresis at high temperature. This will result in a good wear resistance and rolling resistance compromise for the tires. With regard to wet skid resistance, the increased friction 10 12.0 10.0 8.0 6.0 4.0 2.0 G', MPa Silica N134 CRX2124 CRX2124/TESPT 1.0 phr NR, Filler: 50 phr 70°C, 10 Hz
coefficient at high load by CSDPF 2000 suggests the potential for using this material in truck tire tread compounds to improve wet skid resistance. In contrast, the high-silicacoverage <strong>of</strong> CRX 4000 should reduce the micro-elasto-hydrodynamic lubrication, which is favorable for wet skid resistance <strong>of</strong> passenger tire. Therefore, in order to improve the global compromise in tire tread performance, the CSDPF 4000 type <strong>of</strong> material is recommended for passenger tires, and the CSDPF 2000 type for truck tire tread formulations. Application <strong>of</strong> CSDPF CRX4210 to tread compounds for passenger tires CRX4210 was evaluated using typical passenger tire tread formulations which are based on a polymer blend <strong>of</strong> oil-extended solution SBR and BR (Table II). Besides CRX4210, two conventional fillers were included as controls: carbon black N234 and precipitated silica Z1165MP. The filler loading was adjusted to have an equal volume fraction, and the coupling agent TESPT and curatives were also adjusted for CRX4210 and silica compounds to optimize the polymer-filler interaction and filler-filler interaction as well as cure characteristics. Since the stress-strain properties <strong>of</strong> all compounds fall in the practical range, the discussion will be focused on the dynamic properties, abrasion resistance and skid behavior. Table II. Formulations for Passenger Tire Tread Compounds OE-SSBR (Buna VSL 5025-1) 96.3 96.3 96.3 BR 30 30 30 Silica Z1165 80 - - <strong>Carbon</strong> black N234 - 72 - CSDPF CRX4210 - - 72 Coupling agent TESPT 6.4 - 2.7 Aromatic Processing Oil 1.8 1.8 1.8 Zinc Oxide 3.0 3.0 3.0 Stearic Acid 2.0 2.0 2.0 Antioxidant (Sant<strong>of</strong>lex 13) a 1.0 1.0 1.0 Antioxidant (Wingstay 100) b 1.0 1.0 1.0 Wax (Sunpro<strong>of</strong> Imp) 3.5 3.5 3.5 CBS c 2.0 1.1 1.6 DPG d 2.1 0.3 0.7 Sulfur 1.4 1.4 1.4 a. N-1,3-dimethyl-butyl-N’-phenyl –p- phenylenediamine. b. Diaryl-p-phenylenediamine. c. N-cyclohexyl-2-benzothiazolesulfenamide. d. 1,3-diphenylguanidine 11
Page 1 and 2: Effect of<
Page 3 and 4: carbon blacks to improve the trade<
Page 6 and 7: Table I. Analytical properties <str
Page 8 and 9: Before ashing After ashing Figure 4
Page 12 and 13: 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2
Page 14 and 15: Wet skid resistance: The results <s
Page 17 and 18: compounds. With this filler, the hi
Page 19 and 20: 140 120 100 80 60 40 20 0 Wet skid

Effect of Functionalization of Carbon Black on Rubber Properties

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