Silica-silane reinforced passenger car tire treads : effect of silica morphology, silica-polymer interface structure and rubber matrix network on tire-performance indicators

Abstract

With references -With summary in English and Dutch.Copy right © Ernest Cichomski, 2015.All right reserved. Cover design by Ernest CichomskiPrinted by Print Partners Ipskamp, P.O. Box 333, 7500 AH Enschede, the Netherlands. Researchers at I. G. Farben, a German conglomerate that included Bayer, focused on the sodium polymerization of the monomer butadiene to produce a synthetic rubber called "Buna" ("bu" for butadiene and "na" for natrium, the chemical symbol for sodium). SILICA-SILANE REINFORCED PASSENGER CAR TIRE TREADS 2The brake-trough came with the discovery in 1929 that Buna S (butadiene and styrene randomly co-polymerized in emulsion), when compounded with carbon black, was significantly more durable than natural rubber.Carbon black can be considered as a one of the oldest manufactured products and its usage as a pigment of India inks and mural paints can be traced back to the ancient Chinese and Egyptians. The most important event which had the greatest influence on the usage of carbon black occurred at the beginning of the former century and involved the discovery of the reinforcing effect of carbon blacks when added to natural rubber, a discovery that was to become one of the most significant milestones in the rubber and automotive industry. By using carbon black as a reinforcing filler the service life of a tire was greatly increased, ultimately making it possible to achieve a range of several ten thousand kilometers. 3Since the early nineteen-forties, carbon blacks have been complemented by the group of highly active silicas. Technological reasons have long prevented silicas from being used in tire compounds. Conventionally, carbon black is considered to be a more effective reinforcing filler for rubber tire treads than silica, if the silica is used without a coupling agent. In comparison with carbon black there tends to be a lack of, or at least an insufficient degree of physical and/or chemical bonding between the silica particles and the rubber. This is necessary to enable the silica to become a reinforcing filler for the rubber for most purposes, including tire treads. To overcome such deficiencies, additives capable of reacting with both the silica surface and the rubber molecules, generally known as coupling agents became a necessity during compounding 4 . Silica offers several advantages over carbon black. In tire treads, silica yields a comparable wear resistance and better wet grip in combination with a lower rolling resistance than carbon black when used in combination with a coupling agent 5,6 .Since rubber and carbon black are both hydrophobic substances, problems rarely arise when the two are mixed. When silica is mixed however with the commonly used non-polar, olefinic hydrocarbon rubbers, there will be a greater occurrence of hydrogenbond interactions between surface silanol groups in silica agglomerates than of interactions between polar siloxane or silanol groups and the rubber, so mixing silica with rubber involves major problems 7 . For this reason there is great intere...

Effect of used motor oil as a rejuvenator on crumb rubber modifier’s released components to asphalt binder

“…22 Silica was used as a filler, a partial substitution of CB, in the rubber industry. 23 Dating back to the 1960s, sulfur-containing silanes had been used as coupling agents to introduce a reinforcement in mineral filled rubbers in order to enhance the chemical binding process between silica as a filler and silica as a rubber, since it is difficult to mix silica as a hydrophilic with rubber as a hydrophobic material. 24,25 b. FTIR spectrum for UMO:…”

The Investigation of the Silica-Reinforced Rubber Polymers with the Methoxy Type Silane Coupling Agents

“…As a result, the effect of surface modification on silica became greater and the hydrophobicity of silica increased, leading to suppressed reagglomeration and reduced scorch generation. Moreover, in the comparison between the methoxy-type SCAs, fewer agglomerates were produced, Mooney viscosity was reduced, and the improvement (T max –T min ) in the vulcanization characteristics was greater in DMSPD than in TMSPD, because the former has fewer lateral methoxy groups than the latter, and therefore, the hydrophilicity of the modified silica was weaker [ 25 ]. The WMB samples had a higher value of the difference between the maximum and minimum torques (T max – T min) than the DMB samples, which demonstrated the property enhancement due to curing was considered to be greater.…”

“…DIN abrasion values of WMB samples were 131 and 137 mg, respectively, and their modulus values were also higher than those of sample T-1. These results may be attributed to the successful optimization of the WMB process with the removal of residual emulsifiers and the sufficient surface modification (i.e., silanization) of the prepared silica cake [ 25 ]. In the case of WMB, a much higher production efficiency was also achieved under a mild mixing temperature and a short mixing time as illustrated in the materials and methods section.…”

“…As a result, the effect of silica surface modification was significant, and the higher degree hydrophobicity of silica allowed higher compatibility with SBR. In the comparison between the methoxy-type samples, a reduced number of methoxy groups was more desirable, because fewer methoxy groups bonding with silica led to decreased methanol byproduct generation (see Figure 9 ), which prevented the weakening of the bond strength between the SBR and the silica surface [ 25 ]. Furthermore, as the number of methoxy groups decreased, the effect of steric hindrance became less significant owing to the simple side structure consisting of methyl groups [ 25 ].…”

“…In the comparison between the methoxy-type samples, a reduced number of methoxy groups was more desirable, because fewer methoxy groups bonding with silica led to decreased methanol byproduct generation (see Figure 9 ), which prevented the weakening of the bond strength between the SBR and the silica surface [ 25 ]. Furthermore, as the number of methoxy groups decreased, the effect of steric hindrance became less significant owing to the simple side structure consisting of methyl groups [ 25 ]. Therefore, SCAs were be able to bond to the silanol groups of the silica surface more densely despite the smaller number of alkoxy groups [ 26 ].…”