scholarly journals Effect of the Functional Group Position in Functionalized Liquid Butadiene Rubbers Used as Processing Aids on the Properties of Silica-Filled Rubber Compounds

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2698
Author(s):  
Donghyuk Kim ◽  
Gyeongdong Yeom ◽  
Hongil Joo ◽  
Byungkyu Ahn ◽  
Hyunjong Paik ◽  
...  

Recently, research conducted on tread compounds with liquid butadiene rubber (LqBR) have been conducted in the tire industry. In particular, the introduction of functional groups into LqBRs is expected to lower hysteresis loss caused by the free chain ends of LqBR. To study this, LqBRs with functional groups at different positions were synthesized. The occurrences of in-chain and chain-end functionalization of functionalized LqBRs (F-LqBRs) were confirmed, the microstructure and functionalization efficiency of F-LqBRs were calculated through the characterizations. This novel functionalization technology was beneficial not only to immobilizing the free chain ends of LqBRs to the surfaces of silica to decrease the number of free chain ends, but also chemically bonding the LqBR chains on the base polymer through a crosslinking reaction to enhance the filler-rubber interaction. The effects of the functional group position and number of the free chain ends on the physical properties and hysteresis of the compounds were investigated by partially replacing the treated distillate aromatic extract (TDAE) oil with LqBR in silica-filled rubber compounds. The results showed that compounds that had applied DF-LqBR with both end functionalization performed better, including improving the silica dispersion, higher extraction resistance, and lower rolling resistance, than other F-LqBRs 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.


2017 ◽  
Vol 90 (3) ◽  
pp. 508-520 ◽  
Author(s):  
Amirhossein Mahtabani ◽  
Mohammad Alimardani ◽  
Mehdi Razzaghi-Kashani

ABSTRACT The present study discusses that filler–filler mechanical engagement resulting from the grafted long-chain silanes on the silica surface is indeed a reinforcing mechanism in rubber composites, as already speculated by nonlinear viscoelastic properties in our previous study. The existence and severity of such a phenomenon are assessed purely by isolating the energetic contribution of reinforcement from interfering with filler mechanical engagement in the silica network formation and breakdown processes. In a novel approach, the driving force of fillers to flocculate energetically at elevated temperatures was defined using surface energy theories, and it was adjusted to be similar in two composites having silica treated by short- and long-chain silanes. Filler–filler mechanical engagement was monitored by tracking network formation (filler flocculation) in a matrix of styrene–butadiene rubber and also by conducting various dynamic viscoelastic experiments on liquid paraffin suspensions having short- and long-chain silica of similar surface energy. Results consistently confirmed the existence of mechanical engagement between silica particles having the long-chain silane in both rubber compounds and paraffin suspensions. The results may find applications in the rolling resistance of tires, for example, where stabilization of the filler network by displacing the peak energy dissipation of the network breakdown from applied service strains to larger values would be of technical importance.


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.


2020 ◽  
Vol 856 ◽  
pp. 169-174
Author(s):  
Chatchatree Thongsaen ◽  
Pongdhorn Sea-Oui ◽  
Chakrit Sirisinha

Solution styrene-butadiene rubber (SSBR) reinforced by hybrid fillers of carbon black (CB) and silica (PSi) was prepared with various CB/PSi ratios. Rheological and mechanical properties of rubber compounds and vulcanisates were investigated. Results of compounds demonstrate that, with increasing CB fraction, increases in the magnitude of the Payne effect and Mooney viscosity were found. On the contrary, with increased loading of PSi, increases in optimum cure time (tc90) and cure torque difference were evidenced. The results suggest superiority in filler dispersion level and cure efficiency in the systems filled with high PSi fraction due to the presence of Bis [3-(triethoxysilyl) propyl] tetrasulphide (TESPT or Si-69) as a silane coupling agent. As for vulcanisate properties, the systems with increased PSi fraction exhibit enhancement in mechanical strength and elastic contribution, which are in good agreement with rubber compound properties. Also, the decrease in loss factor at 60 °C was observed with increasing PSi fraction, suggesting the desirable reduction in rolling resistance of tyre tread.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1000 ◽  
Author(s):  
Hyunsung Mun ◽  
Kiwon Hwang ◽  
Eunho Yu ◽  
Woong Kim ◽  
Wonho Kim

In the tire industry, solution styrene butadiene rubber (SSBR), which can introduce a functional group with good reactivity to silica at chain ends, is used to increase rolling resistance performance by considering fuel economy. However, this is not environmentally friendly because SSBR uses an organic solvent for polymerization, and it is difficult to increase its molecular weight. Functionalized emulsion SBR (ESBR) can solve the problems of SSBR. The molecular weight of ESBR molecules can be easily increased in an eco-friendly solvent, i.e., water. A functionalized ESBR introduces a functional group with good reactivity to silica by introducing a third monomer during polymerization. In this field, glycidyl methacrylate (GMA) has been reported to show the best properties as a third monomer. However, for GMA-ESBR, the viscosity is high and processability is disadvantageous. Therefore, we polymerized GMA-ESBR and manufactured silica compounds to clarify the causes of these problems. In addition, wet masterbatch (WMB) technology, which is a new compound manufacturing method, was applied to manufacture the silica compound, and the physical properties are compared with those of a dry masterbatch. The results clarified the problem of GMA-ESBR, which could be solved by using WMB technology.


2021 ◽  
pp. 009524432098815
Author(s):  
Viviane Meyer Hammel Lovison ◽  
Maurício Azevedo de Freitas ◽  
Maria Madalena de Camargo Forte

Silica-filled styrene butadiene rubber (SBR)/butadiene rubber (BR) compounds plasticized with mineral oils are mainly used to produce green tire treads. Previous works have demonstrated that the partial replacement of naphthenic oil (ONAF) by bio-based oils can provide processing and performance improvements for rubber compounds, along with environmental benefits. In this study, two modified soybean oils (esterified, OEST or esterified and epoxidized, OEPX) were investigated with the aim of evaluating the complete replacement of ONAF and determining whether the chemical properties of the oils affect the performance of silica-filled E-SBR/BR compounds, using the compound with ONAF as a reference. The physical properties, curing characteristics, morphology, and dynamic mechanical behavior were evaluated. The use of the modified soybean oils decreased the optimal cure time while increasing the crosslink density and the abrasive wear resistance. Further, the compounds with both modified soybean oils showed a good balance of mechanical properties. The modified soybean oils decreased the glass transition temperature of the rubber compounds, thus acting as true plasticizers. At 0°C, the tan δ value of E-SBR/BR/OEPX increased relative to that of E-SBR/BR/ONAF, whereas at 60°C, the values of the compounds with both modified soybean oils showed slight increases. The tan δ values reveal that compared with E-SBR/BR/ONAF, E-SBR/BR/OEPX has better wet grip and a similar rolling resistance, whereas E-SBR/BR/OEST has a higher rolling resistance. Thus, both modified soybean oils can fully replace ONAF and appear to be extremely attractive plasticizers for use in silica-filled E-SBR/BR compounds employed as green tire treads for passenger cars.


2020 ◽  
pp. 096739112097139
Author(s):  
Sung Ho Song

Carbon black has been replaced with silica as a reinforcing filler in tire tread compounds. This change has led to lower rolling resistance and improved hysteretic losses of so-called “green tires.” However, the dispersion of silica in the rubber matrix is an important issue due to the poor compatibility of hydrophilic silica with a hydrophobic rubber matrix. Recently, some rubbers with polar functional groups that can interact with silica have been studied to improve the interaction in silica-filled rubber composites. In this work, we fabricated the silica-filled rubber composites with solution styrene butadiene rubber (SSBR) and epoxidized natural rubber (ENR) and evaluated their properties in a silica-containing rubber formulation compared to conventional SBR and NR. The silica-embedded polar rubber matrix exhibits remarkable enhancement in the modulus, tensile strength, and abrasion properties due to an efficient dispersion of the silica and improvement of interfacial interactions with the rubber matrix. The polar rubber composite exhibits an enhanced dry and wet braking and improved rolling resistance due to the improved dispersion of the silica in the rubber matrix. These results show that rubber composites prepared with polar rubbers have great potential for tire engineering applications.


2014 ◽  
Vol 1024 ◽  
pp. 175-178
Author(s):  
Mazlina Mustafa Kamal ◽  
Dayang Habibah Abang Asmawi

Since the introduction of the so-called Green Tyre concept, in the early 90ies, the use of silica as reinforcing fillers has spread and grown worldwide. The general advantages of silica as reinforcing filler over carbon black filler are better rolling resistance by achieving at least equal wet traction while tread wear should not be adversely affected. One way to obtain both low rolling resistance and high wet traction is indeed, to use precipitated silica together with solution polymers in tyre treads. The benefits of reinforcement by silane coupled silicas, in certain blends of solution styrene –butadiene rubber (SBR) and butadiene rubber (BR), were recognized by major tyre manufacturer. However, the use of silica compounds entails considerable disadvantages in terms of raw material costs and processability (before vulcanization). These difficulties include higher compound Mooney Viscosity (ML1+4) that increases upon storage, short scorch time and environmental problems related to alcohol evolution. The high viscosity and poor processability in silica filled rubber compounds are believed to be associated with silica reaggregation (self aggregation) after rubber compounding. The study has been made of the effect of increased mixing stage and dispersion agent in rubber on uncured properties of the Silica Filled Epoxidised Natural Rubber Compounds. In this experiment, two orders of mixing were considered (1) Two Stages Mixing and (2) Three Stages Mixing. Results showed that filler dispersion, Mooney Viscosity and Payne Effect was influenced by the degree of mixing. The incorporation of dispersion agents in the compounds also resultant in the similar manner. It is believed that the dispersion agent could coat the silica surfaces as they are being broken down during the mixing and then stabilize the dispersed structure by stearically preventing silica reagglomeration.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2815
Author(s):  
Sangwook Han ◽  
Bonyoung Gu ◽  
Sungwoo Kim ◽  
Seongrae Kim ◽  
Dalyong Mun ◽  
...  

The vulcanizate structure of filled compounds is affected by filler–rubber interactions (FRI) and the chemical crosslink density (CCD) of the matrix rubber. In particular, in filled compounds using a silica–silane system, FRIs due to silica–rubber coupling are a major influencing factor for the vulcanizate structure and physical properties. In this study, the effect of sulfur variation on the vulcanizate structure of silica-filled solution styrene–butadiene rubber compounds using a sulfide–silane coupling agent was studied. The vulcanizate structure according to sulfur variation was quantitatively analyzed using the swelling test and Flory–Rehner and Kraus equations. As the sulfur content increased, both FRI and the CCD increased, and it was confirmed that sulfur variation influenced the silica–rubber coupling efficiency through increased FRI. In addition, field emission scanning electron microscope images showed that increased FRI contributed to improvements in silica dispersion, abrasion resistance, and energy loss characteristics.


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