REACTIVITY STUDY OF MERCAPTO–SILANE AND SULFIDE–SILANE WITH POLYMER

2019 ◽  
Vol 93 (2) ◽  
pp. 319-345
Author(s):  
Masaki Sato ◽  
Satoshi Mihara ◽  
Naoya Amino ◽  
Wilma K. Dierkes ◽  
Anke Blume

ABSTRACT Mercapto–silanes enable an improved silica dispersion state compared with sulfide–silanes in tire tread compounds, which causes a better balance of wet grip and rolling resistance. However, it also causes a higher Mooney viscosity and a shorter scorch time, which results in processing difficulties. The reason for this behavior is not clear. Because the already deeply investigated silica–silane reaction cannot explain the observed effects, the silane–polymer reaction was considered to be responsible and therefore has been evaluated in depth. The reaction between mercapto–silane or sulfide–silane and an olefin instead of a rubber was investigated in terms of reaction possibilities, mechanism, and kinetic aspects by varying the structure of the olefin. The results reveal that mercapto–silanes and sulfide–silanes affect olefins in different ways depending on the structure of the olefin. These results were compared with those in actual tire tread compounds in terms of the in-rubber properties such as the Payne effect and Mooney viscosity. It was confirmed that the different sulfur functions of the silanes interact in a different way with the polymer, which has a significant influence on the processability, silica dispersion state, and also rolling resistance indicator of the final rubber compound.

2013 ◽  
Vol 781-784 ◽  
pp. 475-478
Author(s):  
Watcharin Rassamee ◽  
Woothichai Thaijaroen ◽  
Thirawudh Pongprayoon

Natural rubber compound using different silicas, including unmodified silica, admicellar-modified silica and silica with silane coupling agent, were studied. The properties including cure characteristics, mechanical properties and dynamic properties were examined with the comparison of three compounds. The results show that cure characteristics of admicellar silica/rubber compound (Ad-Si/R) was shorter than those of unmodified silica/rubber compound (Un-Si/R) and silane coupling silica/rubber compound (Sil-Si/R). Mechanical properties of Ad-Si/R and Sil-Si/R were better than those of Un-Si/R. In addition, wet grip and rolling resistance analyzed from tan δ (5 Hz) at 0°C and 60°C, respectively, by DMA were found that the wet grip of Ad-Si/R was the best, whereas the rolling resistance of Sil-Si/R was the best, in the comparison.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 788
Author(s):  
Minghan Xu ◽  
Hao Xue ◽  
Wit Yee Tin ◽  
He Wang ◽  
Zhanfu Yong ◽  
...  

The viscoelastic behavior and reinforcement mechanism of polyethylene glycol (PEG) as an interfacial modifier in green tire tread composites were investigated in this study. The results show a clear positive effect on overall performance, and it significantly improved all the parameters of the “magic triangle” properties, the abrasion resistance, wet grip and ice traction, as well as the tire rolling resistance, simultaneously. For the preparation of the compounds, two mixing steps were used, as PEG 4000 was added on the second stage in order to avoid the competing reaction between silica/PEG and silanization. Fourier transform infrared spectroscopy (FTIR) confirmed that PEG could cover the silanol groups on the silica surface, resulting in the shortening of cure times and facilitating an increase of productivity. At low content of PEG, the strength was enhanced by the improvement of silica dispersion and the slippage of PEG chains, which are chemically and physically adsorbed on silica surface, but the use of excess PEG uncombined with silica in the compound, i.e., 5 phr, increases the possibility to shield the disulfide bonds of bis(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT), and, thus, the properties were deteriorated. A constrained polymer model was proposed to explain the constrained chains of PEG in the silica-loaded composites on the basis of these results. An optimum PEG content is necessary for moderately strong matrix–filler interaction and, hence, for the enhancement in the mechanical properties.


2012 ◽  
Vol 9 (3) ◽  
pp. 1102-1112 ◽  
Author(s):  
Ramin Zafarmehrabian ◽  
Saeed Taghvaei Gangali ◽  
Mir Hamid Reza Ghoreishy ◽  
Mehran Davallu

NR is the major constituent in the rubber compound used for the tread on the truck tires. A general compound formulation of the tire tread includes NR and BR as polymer base and carbon black as the reinforcing filler, and curative components. In this paper the effects of dual filler system (carbon black and precipitated silica) on the dynamic properties of tire treat has been studied. The results show by increasing of precipitated silica, significant improvement was observed in fatigue resistance, rolling resistance and heat buildup of the tire. Tensile strength and modulus and wet grip of tire tread decrease with increasing of silica in rubber compound formulation.


2021 ◽  
pp. 009524432110290
Author(s):  
Leandro Hernán Esposito ◽  
Angel José Marzocca

The potential replacement of a treated residual aromatic extract mineral oil (TRAE) by a highly epoxidized soybean oil (ESO) into a silica-filled styrene-butadiene rubber compound was investigated. In order to determine if ESO compounds performance are suitable for tread tire applications, processing properties cure and characteristics were evaluated. The impact of ESO amount on the silica dispersion was confirmed by Payne Effect. The presence of chemical or physical interactions between ESO and silica improves the filler dispersion, enabling the compound processability and affecting the cure kinetic rate. An adjusted rubber compound with 2 phr of ESO and 2 phr of sulfur presented the higher stiffness and strength values with lower weight loss from a wear test compared with TRAE compound at an equal amount of oil and curing package. Furthermore, wet grip and rolling resistance predictors of both compounds gave comparable results, maintaining a better performance and reducing the dependence of mineral oil for tire tread compounds.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 850
Author(s):  
Donghyuk Kim ◽  
Byungkyu Ahn ◽  
Kihyun Kim ◽  
JongYeop Lee ◽  
Il Jin Kim ◽  
...  

Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization. In addition, LqBR was added to the silica-filled SSBR compounds as an alternative to treated distillate aromatic extract (TDAE) oil, and the effect of molecular weight and functionalization on the properties of the silica-filled SSBR compound was examined. C-LqBR showed a low Payne effect and Mooney viscosity because of improved silica dispersion due to the ethoxysilyl functional group. Furthermore, C-LqBR showed an increased crosslink density, improved mechanical properties, and reduced organic matter extraction compared to the N-LqBR compound. LqBR reduced the glass transition temperature (Tg) of the compound significantly, thereby improving snow traction and abrasion resistance compared to TDAE oil. Furthermore, the energy loss characteristics revealed that the hysteresis loss attributable to the free chain ends of LqBR was dominant.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Sattayanurak ◽  
J. W. M. Noordermeer ◽  
K. Sahakaro ◽  
W. Kaewsakul ◽  
W. K. Dierkes ◽  
...  

Modern fuel-saving tire treads are commonly reinforced by silica due to the fact that this leads to lower rolling resistance and higher wet grip compared to carbon black-filled alternatives. The introduction of secondary fillers into the silica-reinforced tread compounds, often named hybrid fillers, may have the potential to improve tire performance further. In the present work, two secondary fillers organoclay nanofiller and N134 carbon black were added to silica-based natural rubber compounds at a proportion of silica/secondary filler of 45/10 phr. The compounds were prepared with variable mixing temperatures based on the mixing procedure commonly in use for silica-filled NR systems. The results of Mooney viscosity, Payne effect, cure behavior, and mechanical properties imply that the silica hydrophobation and coupling reaction of the silane coupling agent with silica and elastomer are significantly influenced by organoclay due to an effect of its modifier: an organic ammonium derivative. This has an effect on scorch safety and cure rate. The compounds where carbon black was added as a secondary filler do not show this behavior. They give inferior filler dispersion compared to the pure silica-filled compound, attributed to an inappropriate high mixing temperature and the high specific surface area of the carbon black used. The dynamic properties indicate that there is a potential to improve wet traction and rolling resistance of a tire tread when using organoclay as secondary filler, while the combination of carbon black in silica-filled NR does not change these properties.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Chakrit Sirisinha ◽  
Wenussarin Intiya ◽  
Pram Yodjun ◽  
...  

This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR) and butadiene rubber (BR) and SBR type (E-SBR and S-SBR) on properties of SBR/BR tire tread compounds. Influences of these parameters on properties of the tread compounds reinforced by 80 parts per hundred rubber (phr) of carbon black (CB) and silica were also compared. Results reveal that hardness, strengths, and wet grip efficiency were impaired whereas rolling resistance was improved with increasing BR proportion. Surprisingly, the presence of BR imparted poorer abrasion resistance in most systems, except for the CB-filled E-SBR system in which an enhanced abrasion resistance was observed. Obviously, S-SBR gave superior properties (tire performance) compared to E-SBR, particularly obvious in the silica-filled system. Compared with CB, silica gave comparable strengths, better wet grip efficiency, and lower rolling resistance. Carbon black, however, offered greater abrasion resistance than silica.


1985 ◽  
Vol 58 (1) ◽  
pp. 67-85 ◽  
Author(s):  
C. S. L. Baker ◽  
I. R. Gelling ◽  
R. Newell

Abstract When natural rubber is epoxidized under carefully controlled conditions, it can be converted to a totally new polymer with some properties more akin to speciality rubbers and some properties that appear to be advantageous for tire treads. Three levels of epoxidation have been extensively evaluated. They were 50, 25 and 10 mole% epoxidized NR referred to as ENR-50, ENR-25 and ENR-10 respectively. ENR-50 has been found to undergo strain crystallization like NR, but with oil resistance similar to a medium acrylonitrile NBR and gas permeability similar to butyl rubber. It is a highly damping rubber with a very low room-temperature resilience. ENR-50 and ENR-25 both exhibit good wet grip characteristics and have been examined as tire tread materials. In particular, ENR-25 compounds containing silica or silica/black have been found to give lower rolling resistance than NR and better wet traction than OESBR, so providing an ideal combination of these two properties for tire treads. Unfortunately, wear data is as yet incomplete, but it is anticipated, from truck tire experience, that the black/silica compounds will present no problems. ENR-25 and ENR-50 exhibit this unique feature with silica of reinforcement equivalent to black without the use of a coupling reagent. Thus, these rubbers have potential of providing white or colored vulcanizates with properties previously associated only with black-filled compounds, so extending applicational areas, or even resulting in colored tires or other automotive parts. ENR-10 provides a damping grade of NR when lower resiliences are required. Alternatively, blends of ENR-25 or -50 with NR may be used. Many engineering applications are calling for reduced resilience, and this new form of NR can give precisely this.


Author(s):  
Jingwei Zhang ◽  
Jianmin Lu ◽  
Dongfang Wang ◽  
Bingyong Han

ABSTRACT To overcome the problem of fossil fuel depletion and associated environmental issues arising from the use of tire tread elastomers, a convenient, environmentally friendly, and highly efficient strategy was developed to prepare high-performance green solution polymerized styrene–butadiene rubber (SSBR)/silica nanocomposites by improving silica dispersion in the nonpolar polymer matrix via the introduction of a biobased nonpolar bottlebrush segment with two double bonds. Various elastomers containing biobased nonpolar bottlebrush β-myrcene segments were synthesized using an industrially robust anionic polymerization method. Results of robotic process automation, small-angle X-ray scattering, scanning electron microscopy, and transmission electron microscopy revealed that rubber with myrcene could significantly improve silica dispersibility and inhibit the strong filler–filler interactions, which are due to the formation of hydrogen bonding between the double bonds in the myrcene block and silanol groups on the silica surface and possibly to the spreading or infiltrating of myrcene bottlebrush segments onto silica. Furthermore, for the modified rubber, rolling resistance decreased by 41.7%, tear strength increased by 20.78%, and tensile strength increased by 77.8% with the elongation at break remained practically unchanged as compared with the unmodified silica/SSBR composite. On the basis of aforementioned assessment, we believe that silica-reinforced β-myrcene–based styrene–butadiene integrated rubber is a versatile and promising candidate for future tire tread elastomers.


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