Synthesis and utilization of epoxidized polybutadiene rubber as an alternate compatibilizer in green-tire composites

Abstract

In the present study, epoxidized polybutadiene rubber (EBR) was synthesized from commercial-grade cispolybutadiene rubber (BR) and was characterized by NMR, FTIR, differential scanning calorimetry, thermogravimetric analysis and surface energy by contact angle measurement. To circumvent the drawback of the existing compatibilizers, the EBR was successfully used as an alternate compatibilizer for a silica-based 'green-tire' composite. The significant rise of surface energy was observed after epoxidation of BR, which represents the enhancement of the polar character of the rubber chains and eventually leads to improved compatibility between silica fillers and rubber chains. Out of various epoxidation levels, EBR with 30 mol% epoxidation showed the best compatibilizing effect. The optimum loading of EBR was found to be 12% with respect to total silica content. Apart from using EBR alone as a compatibilizer, combination of EBR with commercial silane-coupling agents, namely, bis(triethoxy-silylpropyl) tetrasulphide (TESPT) and 3-aminopropyltrimethoxy silane, was also investigated. The physico-mechanical and dynamic properties of the compounds with a combination of were comparable with those of the compound prepared using TESPT compatibilizer. The results observed with EBR-compatibilized samples revealed that EBR has a potential to be an effective compatibilizer which eventually could minimize the drawbacks associated while using commercial silane as a compatibilizer at the industrial scale.

A critical review on the utilization of various reinforcement modifiers in filled rubber composites

“…However, there are still some major disadvantages regarding the application of silane coupling agent as reinforcement modifier like production of alcohol as by-products during coupling reaction, higher prices of silane coupling agents, and difficult processing behavior. 57 Thus, the discovery of alternative reinforcement modifiers in place of silane is important issue in rubber industry.…”

“…In the recent 5 years, different researchers reported the use of some suitable alternative compatibilizers in silica-filled rubber composites. [57][58][59][60] Srivastava et al 57 discussed the use of epoxidized polybutadiene rubber (EBR) as effective compatibilizer for silica-filled green styrene-butadiene rubber (SBR)/BR composites. The compatibilizing effect was highest in presence of EBR with 30 mol% epoxidation level (EBR30).…”

“…Kaewsakul et al 55 TESPT It can able to improve rubber-filler interaction and mechanical properties of silica-filled NR compounds Srivastava et al 57 TESPT: EBR (40:60) It can able to act as compatibilizer to improve physicomechanical and dynamic properties of silica-filled SBR/BR composites Sengloyluan et al 58…”

Influence on mechanical and rheometric properties through different methods of chemical modification of silica applied to natural rubber compounds

“…However, precipitated silica also improves dynamic properties and reduces heat generation, which is why these factors are being used to produce so-called green tires. 9 –11 Silica is obtained by a chemical reaction between sand and sodium hydroxide, resulting in a sodium silicate suspended in water, which goes through the precipitation, cleaning, filtration, and drying processes. 8…”

Preparation of dispersible nanosilica surface‐capped by hexamethyl disilazane via anin situsurface‐modification method and investigation of its effects on the mechanical properties of styrene–butadiene/butadiene rubber

“…used a phosphonium ionic liquid as a catalyst for a silanization reaction; the composite showed a lower energy loss and improved interfacial interactions. In addition, various strategies, including wrapping silica with a surfactant and covalently grafting silica with coupling agent or polymer chain, have been used to explore the surface properties of silica . To date, silica as an alternate filler has advantages in getting rid of environmental issues in the rubber industry.…”