TIME AND TEMPERATURE DEPENDENT PIEZORESISTIVE BEHAVIOR OF CONDUCTIVE ELASTOMERIC COMPOSITES

ABSTRACT We report about systematic studies on dynamic piezoresistive characteristics of conductive rubber composites. The temporal changes in electrical resistance of flexible electrically conductive rubber composites were simultaneously monitored during dynamic mechanical loading. Thus, influences of physical parameters such as frequency, temperature, strain amplitude, and matrix stiffness were explored in detail, and the mechanisms behind qualitatively discussed. The filler clusters were found to rearrange in the elastomer matrix during dynamic deformation, witnessed by the decrease in electrical resistance over time. Each test parameter had its own specific effect on the piezoresistance response, and the findings offered an understanding on the filler networking inside the solution styrene butadiene rubber matrix from the perspective of the dynamic piezoresistive characteristics. Higher piezoresistive response was observed near the glass transition temperature. We offer a deeper insight into the behavior and temporal changes in corresponding filler clusters during dynamic deformations of conducting rubber systems.

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Influence of Eco-Friendly Processing Aids on Silica-Based Rubber Composites

Applied Sciences ◽

10.3390/app10207244 ◽

2020 ◽

Vol 10 (20) ◽

pp. 7244

Author(s):

Sung Ho Song

Keyword(s):

Mechanical Properties ◽

Rolling Resistance ◽

Fatigue Properties ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Dispersing Agent ◽

Styrene Butadiene ◽

Processing Aids

As eco-friendly “green tires” are being developed in the tire industry, conventionally used carbon black is being replaced with silica in rubber compounds. Generally, as a lubricant and dispersing agent, processing aids containing zinc ions have been employed as additives. However, as zinc is a heavy metal, alternative eco-friendly processing aids are required to satisfy worldwide environmental concerns. Furthermore, non-toxic, degradable, and renewable processing aids are required to improve the mechanical properties of the rubber composites. In this study, we evaluated the effects of diverse silica-based processing aids containing hydrocarbon, benzene, and hydroxyl functional groups on the mechanical properties of rubber composites. Among them, rubber composites that used amphiphilic terpene phenol resin (TPR) with hydrophilic silica showed compatibility with the hydrophobic rubber matrix and were revealed to improve the mechanical and fatigue properties. Furthermore, owing to the enhanced dispersion of silica in the rubber matrix, the TPR/styrene butadiene rubber composites exhibited enhanced wet grip and rolling resistance. These results indicated that TPR had multifunctional effects at low levels and has the potential for use as a processing aid in silica-based rubber composites in tire engineering applications.

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Study on silica-based rubber composites with epoxidized natural rubber and solution styrene butadiene rubber

Polymers and Polymer Composites ◽

10.1177/0967391120971391 ◽

2020 ◽

pp. 096739112097139

Author(s):

Sung Ho Song

Keyword(s):

Natural Rubber ◽

Rolling Resistance ◽

Epoxidized Natural Rubber ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Filled Rubber ◽

Polar Functional Groups ◽

Styrene Butadiene

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.

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Investigation of Epoxidized Palm Oils as Green Processing Aids and Activators in Rubber Composites

International Journal of Polymer Science ◽

10.1155/2019/2152408 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

DongJu Lee ◽

Sung Ho Song

Keyword(s):

Mechanical Properties ◽

Abrasion Resistance ◽

Raw Material ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Green Processing ◽

Styrene Butadiene ◽

Heat Buildup

Epoxidized palm oil (EPO) is environmentally friendly, biodegradable, and a relatively less costly processing aid. In this study, we investigated the suitability of EPO in place of aromatic processing oils in styrene butadiene rubber. The curing properties, mechanical properties, abrasion resistance, and heat buildup properties of rubber composites with EPO were compared with those of the standard with aromatic oils. The rubber composites with EPO showed enhanced mechanical properties including modulus, tensile strength, and elongation at break. This is ascribed to the improved dispersion of fillers in the rubber matrix and interaction between the filler and the polymer. Furthermore, EPO in the rubber matrix showed remarkable abrasion resistance, rebound resilience, and heat buildup at low loadings. EPO in a rubber composite presents feasibility as a renewable raw material that can serve as an alternative to petrochemical oils in various applications.

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Characterization of eco-friendly processing aids for styrene butadiene rubber composites with silica

Journal of Composite Materials ◽

10.1177/0021998320916230 ◽

2020 ◽

Vol 54 (23) ◽

pp. 3405-3413

Author(s):

Sung Ho Song

Keyword(s):

Metal Ion ◽

High Speed ◽

Fatigue Properties ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Tire Industry ◽

Styrene Butadiene ◽

Processing Aids

With the development of environmentally friendly “green tires” in the tire industry, silica has been used as a reinforcing filler material in tread compounds. With regard to this rubber compounding process, non-toxic, and renewable processing aids are required. We fabricated such processing aids with multi-alcohol components of hydrophobic and hydrophilic groups (M-A-S) to make the hydrophilic silica compatible with the hydrophobic rubber matrix. The rubber composites with M-A-S showed remarkable enhancements in the mechanical properties, specifically the tensile strength, elongation and fatigue properties due to the improved dispersion of silica in the rubber matrix. They also exhibited outstanding heat build-up, good rebound resilience, and abrasion levels at low loadings. Furthermore, M-A-S were added directly to tread compounds to make a pneumatic tire with enhanced high-speed durability and enhanced dry and wet braking due to the strong interfacial interaction between the silica and the rubber matrix. These results demonstrate the advantages of the proposed potential replacement for metal-ion processing aids for tire engineering.

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PHYSICOELECTRICAL PROPERTIES AND PIEZORESISTIVE SENSING OF THE EXTRUSION-BASED CONDUCTIVE RUBBER COMPOSITES: SIMULTANEOUS EFFECTS OF THE EXTRUSION PARAMETERS

Rubber Chemistry and Technology ◽

10.5254/rct.20.80392 ◽

2020 ◽

pp. 000-000

Author(s):

Jirawat Narongthong ◽

Pongdhorn Sae-Oui ◽

Manuchet Nillawong ◽

Chakrit Sirisinha

Keyword(s):

Mechanical Strength ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Screw Speed ◽

Soft Matrix ◽

Screw Design ◽

Conductive Rubber ◽

Twin Screw ◽

Styrene Butadiene

ABSTRACT Flexible conductive rubber composites (CRCs) were prepared based on carbon black–filled oil-extended styrene–butadiene rubber soft matrix. Using a variety of screw designs, the simultaneous effects of the twin-screw extrusion parameters (i.e., kneading element, dispersing position, and screw speed) on the physicoelectrical properties of the CRCs were investigated statistically. The increased intenseness of the extrusion parameters significantly enhances the piezoresistive sensing via the improved filler dispersion, increased rubber–filler interaction, and weakened filler–filler networks. Nevertheless, the influence of the kneading elements on the properties of the CRCs significantly decreases with an increase in the intenseness of the dispersing position or the screw speed, referred to as a “negative interaction.” An extreme intenseness of the screw design causes the excellent piezoresistive sensing of the CRCs, but with undesirable mechanical strength. Because those properties need to be balanced, many methods of adjusting the CRCs to be more suitable for strain-sensor application, in terms of not only piezoresistive performance but also mechanical strength, were thus established.

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Novel Hybrid Biomass Anti-Aging Filler for Styrene-Butadiene Rubber Composites with Antioxidative and Reinforcing Properties

Materials ◽

10.3390/ma13184045 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4045

Author(s):

Xiaohui Guo ◽

Yuanfang Luo ◽

Yongjun Chen ◽

Lijuan Chen ◽

Demin Jia

Keyword(s):

Oxidative Stability ◽

Phenolic Hydroxyl ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Composites ◽

Uv Aging ◽

Thermal Oxidative Stability ◽

Aging Resistance ◽

Styrene Butadiene

Antioxidants are normally utilized to extend the service life of polymers due to the strong reducibility of the phenolic hydroxyl group of the hindered phenol structure. Inspired by this characteristic, we have introduced green tea polyphenol (TP) supported on a silica surface containing considerable phenolic hydroxyl groups to obtain a novel biomass anti-aging filler (BAF, denoted as silica-s-TP) to reinforce and improve the anti-aging property of rubber composites. The applying of silica-s-TP to enhance the thermal-oxidative stability and ultraviolet light (UV) aging resistance of styrene-butadiene rubber (SBR) was evaluated. The hybrid biomass anti-aging filler could not only uniformly disperse in the rubber matrix, giving rise to the excellent mechanical properties, but also enhance the properties of thermal-oxidative stability and UV aging resistance with the increasing silica-s-TP content of SBR distinctly. This study provides a mild and environmentally friendly strategy to prepare the functional biomass filler, which could be applied as not only a reinforcement filler but also an anti-aging additive in “green rubber”.

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Preparation of natural bio-based Eucommia ulmoides gum/styrene-butadiene rubber composites and the evaluation of their damping and sound absorption properties

Polymer ◽

10.1016/j.polymer.2020.123292 ◽

2021 ◽

Vol 213 ◽

pp. 123292

Author(s):

Renwei Cao ◽

Linhui Deng ◽

Zhibo Feng ◽

Xiuying Zhao ◽

Xiaolin Li ◽

...

Keyword(s):

Sound Absorption ◽

Styrene Butadiene Rubber ◽

Eucommia Ulmoides ◽

Butadiene Rubber ◽

Rubber Composites ◽

Absorption Properties ◽

Eucommia Ulmoides Gum ◽

Styrene Butadiene

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Hybrid Silica-Based Fillers in Nanocomposites: Influence of Isotropic/Isotropic and Isotropic/Anisotropic Fillers on Mechanical Properties of Styrene-Butadiene (SBR)-Based Rubber

Polymers ◽

10.3390/polym13152413 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2413

Author(s):

Mariapaola Staropoli ◽

Vincent Rogé ◽

Enzo Moretto ◽

Joffrey Didierjean ◽

Marc Michel ◽

...

Keyword(s):

Mechanical Properties ◽

Silica Nanoparticles ◽

Synergetic Effect ◽

Mechanical Analysis ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Precipitated Silica ◽

Scanning Transmission ◽

Styrene Butadiene

The improvement of mechanical properties of polymer-based nanocomposites is usually obtained through a strong polymer–silica interaction. Most often, precipitated silica nanoparticles are used as filler. In this work, we study the synergetic effect occurring between dual silica-based fillers in a styrene-butadiene rubber (SBR)/polybutadiene (PBD) rubber matrix. Precipitated Highly Dispersed Silica (HDS) nanoparticles (10 nm) have been associated with spherical Stöber silica nanoparticles (250 nm) and anisotropic nano-Sepiolite. By imaging filler at nano scale through Scanning Transmission Electron Microscopy, we have shown that anisotropic fillers align only in presence of a critical amount of HDS. The dynamic mechanical analysis of rubber compounds confirms that this alignment leads to a stiffer nanocomposite when compared to Sepiolite alone. On the contrary, spherical 250 nm nanoparticles inhibit percolation network and reduce the nanocomposite stiffness.

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Particle Size, Structure and Powdering Process of Calcium Carbonate Nanoparticles Filled Powdered Styrene-Butadiene Rubber

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.237 ◽

2011 ◽

Vol 415-417 ◽

pp. 237-242

Author(s):

Zhou Da Zhang ◽

Xue Mei Chen ◽

Guo Liang Qu

Keyword(s):

Particle Size ◽

Calcium Carbonate ◽

Size Structure ◽

Average Diameter ◽

Rubber Matrix ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Particle Structure ◽

Styrene Butadiene ◽

New Particles

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.

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