• Elastomers and Composites
• /
• v.20 no.1
• /
• pp.13-24
• /
• 1985

It is generally agreed that strong linkages exist between rubber chains and reinforcing filler particles. The purpose of this study is to examine the effect of rubber-filler attachments on the various mechanical properties of the rubber. In particular, the modulus and strength will be altered by these attachments. For this study, the curing properties are examined by means of ODR (Oscillating Disk Rheometer), the physical properties by means of Instrong. The results of this study can be summarized as follows. In the ODR test, the carbon black filled stock has shorter scorch time than gum stock and, the silica and clay filled stock has longer scorch time than gum stock. In the modulus, ten sile and swelling properties, the vulcanizates filled with carbon black had higher those values than inorganic filler loaded NR vulcanizates, but the rebound rate showed that the silica filled NR vulcanizates was lower than other inorganic filler contained NR vulcanizates and the ISAF filled NR vulcanizates was lower than other carbon block contained NR vulcanizates.

• Elastomers and Composites
• /
• v.22 no.4
• /
• pp.293-304
• /
• 1987

The purpose of this study is to examine the effect of rubber-filler attachments on inorganic filler contained NR vulcanizatic. The results of this study showed as follows. The reinforcing properties and damping values of the vulcanizates in the elastic region showed strong relation with the filler characteristics and temperture. The vulcanizates filled with nature-activated inorganic filler like silica had higer elastic modulus and damping values than the vulcanizates of nature-nonactivated inorganic filter. The reinforcing effects of differential filler loadings on NR raised the effects with temperature rise, but the damping values varied with the filler characteristics and temperature variations.

• Elastomers and Composites
• /
• v.56 no.4
• /
• pp.234-242
• /
• 2021

The demand for truck bus radial (TBR) tires with enhanced fuel efficiency and wear resistance have grown in recent years. In addition, as the issue of particulate matter and air pollution increases, efforts are being made to reduce the generation of particulate matter. In this study, the properties of epoxidized natural rubber (ENR) containing a silica-friendly functional group were evaluated by considering it as a base rubber and varying the silica ratio in this binary filler system. The results showed that the wear resistance of the NR/BR blend compound decreased as the silica ratio increased. In contrast, the ENR/BR blend compound exhibited an increase in wear resistance as the silica ratio was increased. In particular, the ENR-50/BR blend compound showed the best wear resistance due to the presence of several epoxide groups. Furthermore, we observed that for tan 𝛿 at 60℃, higher epoxide content resulted in the higher T_g of the rubber, indicating a higher tan 𝛿 at 60℃. On the other hand, it was confirmed that increasing the silica ratio decreased the value of tan 𝛿 at 60℃ in all compounds. In addition, we measured the amount of wear particulate matters generated from the compound wear. These measurements confirmed that in the binary filler system, regardless of the filler type, the quantity of the generated wear particulate matters as the filler-rubber interaction increased. In conclusion, the silica filled ENR/BR blend compound exhibited the lowest generation of wear particulate matters.

• Elastomers and Composites
• /
• v.45 no.2
• /
• pp.112-121
• /
• 2010

In this study, styrene butadiene rubber(SBR)/organoclay nanocomposites were manufactured using the latex method with 3-aminopropyltriethoxysilane(APTES) as a modifier. The X-ray diffraction(XRD), transmission electron microscopy(TEM) images, Fourier transform infrared(FTIR) spectroscopy, swelling ratio and mechanical properties were measured in order to study the interaction between filler and rubber according to the mixing temperature in the internal mixer. In the case of SBR/APTES-MMT compounds, the dispersion of the silicates within the rubber matrix was enhanced, and thereby, the mechanical properties were improved. The characteristic bands of Si-O-C in APTES disappeared after hydrolysis reaction in the MMT-suspension solution and the peak of hydroxyl group was increased. Therefore the formation of chemical bonds between the hydroxyl group generated from APTES on the silicate surface and the ethoxy group of bis(triethoxysilylpropyl) tetrasulfide(TESPT) was possible. Consequently, the 300% modulus of SBR/APTES-MMT compounds was further improved in the case of using TESPT as a coupling agent. However, the silanization reaction between APTES and TESPT was not affected significantly according to the increase of mixing temperature in the internal mixer.

• Elastomers and Composites
• /
• v.55 no.4
• /
• pp.306-313
• /
• 2020

To investigate the reinforcing effects of functional fillers in nitrile rubber (NBR) materials, high-structure carbon black (HS45), coated calcium carbonate (C-CaCO3), silica (200MP), and multi-walled carbon nanotubes (MWCNTs) were used as functional filler, and carbon black (SRF) as a common filler were used for oil-resistant rubber. The curing and mechanical properties of HS45-, 200MP-, and MWCNT-filled NBR compounds were improved compared to those of the SRF-filled NBR compound. The reinforcing effect also increased with a decrease in the particle size of the fillers. The C-CaCO3-filled NBR compound exhibited no reinforcing effect with increasing filler concentration because of their large primary particle size (2 ㎛). The reinforcing behavior based on 100% modulus of the functional filler based NBR compounds was compared by using several predictive equation models. The reinforcing behavior of the C-CaCO3-filled NBR compound was in accordance with the Smallwood-Einstein equation whereas the 200MP- and MWCNT-filled NBR compounds fitted well with the modified Guth-Gold (m-Guth-Gold) equation. The SRF- and HS45-filled NBR compounds exhibited reinforcing behavior in accordance with the Guth-Gold and m-Guth-Gold equations, respectively, at a low filler content. However, the values of reinforcement parameter (100Mf/100Mu) of the SRF- and HS45-filled NBR compounds were higher than those determined by the predictive equation model at a high filler content. Because the chains of SRF composed of spherical filler particles are similarly changed to rod-like filler particles embedded in a rubber matrix and the reinforcement parameter rapidly increased with a high content of HS45, the higher-structured filler. The reinforcing effectiveness of the functional fillers was numerically evaluated on the basis of the effectiveness index (��SRF/��f) determined by the ratio of the volume fraction of the functional filler (��f) to that of the SRF filler (��SRF) at three unit of reinforcing parameter (100Mf/100Mu). On the basis of their effectiveness index, MWCNT-, 200MP-, and HS45-filled compounds showed higher reinforcing effectiveness of 420%, 70%, and 20% than that of SRF-filled compound, respectively whereas C-CaCO3-filled compound exhibited lower reinforcing effectiveness of -50% than that of SRF-filled compound.

• Elastomers and Composites
• /
• v.50 no.3
• /
• pp.159-166
• /
• 2015

Silica which is used for reinforcing filler in tire industry is widely known as eco-friendly material exerting $CO_2$ reduction effect through decrease of rolling resistance and improvement of wet grip. Generally silica is classified as a highly polar filler because it contains a large number of silanol (Si-OH) group on its surface. And also silica gives a lower reinforcing effect than carbon black due to its poorer rubber-filler interaction. Therefore silica is treated with silane coupling agent or activator, then following the conventional rubber blend method, vulcanized sheets were prepared using a hot press, and cure characteristics, mechanical properties and abrasion resistance of the test specimens were investigated. It was found that with an increase in the silane coupling agent content the tensile strength, 300% modulus and abrasion resistance increased while Mooney viscosity decreased and crosslink density slightly increased with an increase of activator.

• Electrical & Electronic Materials
• /
• v.9 no.4
• /
• pp.344-350
• /
• 1996

Tracking is one of the biggist problems to be overcome in polymeric materials for outdoor insulators. But It can be decreased with the addition of filler such as alumina trihydrate (ATH). In this paper, the tracking of surface and evaluation of insulating ability at silicone rubber is investigated, using the salt fog test. At initial state, the peak leakage current and numbers by dry band arcing is increasing with increasing the filler level, but at aged state decreasing at high concentration filler samples. This is because the roughness of the surface may contribute to the increase in peak leakage cur-rent and numbers. As increasing the filler level, the insulating ability of materials is higher and weight loss is decreased. The mechanism of insulating failure is occurred by the erosion than the tracking and the erosion caused weight loss of 2 g.

• Elastomers and Composites
• /
• v.35 no.2
• /
• pp.132-137
• /
• 2000

The cure and physical properties of EPDM foam containing ground rubber and carbon black as filler were studied. The cure time reduced with the addition of filler. This result means reducing the operation time. In case of ground rubber was used, blowing ratio, tensile strength, and elongation were decreased rapidly at above 30 phr. On the other hand, in case of carbon black, they showed similar physical properties until 70 phr was used limited to 30 phr to make a good foam, which should be due to low interfacial interaction between EPDM and ground rubber. All the EPDM foams showed excellent thermal stability.

• Journal of the Korean Society of Safety
• /
• v.28 no.3
• /
• pp.33-38
• /
• 2013

Many occupational workers or professionals have to walk on the various floors for a long period of time. The objective of this study was to develop the safety shoes with increased traction through the material selection. In order to fulfill our objective, first, two kinds of filler were selected to compare the wear mechanism at outsole surface. The developed rubber materials were tested with two kinds of portable slip meters. The sample safety shoes with developed rubber materials were also tested with subject in the laboratory. During walking, the safety shoes were naturally abraded with counter surface. The coefficient of friction(COF) was gradually decreased with number of steps to 30,000, while the COF was abruptly increased from 30,000 to 40,000. The experimental results showed that COF tested with silica rubber was at least 10% higher than that with carbon black rubber in wet or detergent condition. It has been well recognized that filler properties play a important role in wet traction in the tire industry. However it has been unclear that filler properties would be decisive factor in safety shoes. Our study shows that silica exhibits a higher slip resistance than carbon black without reference to wear states in wet or detergent condition. So, this results will provide guides for outsole compounders to develop new products and improve product performance.

• Elastomers and Composites
• /
• v.47 no.2
• /
• pp.121-128
• /
• 2012

Waste EPDM(W-EPDM) collected from the automotive weather strip and the gasket of a laundry machine has not been effectively recycled. Using this W-EPDM powder and other ingredients, i.e., binder(polyolefin resin, polyolefin elastomer, etc.), filler and additives, various economic rubber composites were made by extrusion. In advance of main experiments, the effects of ultrasonic treatment of W-EPDM on the property of rubber composites, comparison in the property of the composites of W-EPDM with those of virgin and devulcanized EPDM, and waste tire rubber were investigated. Also, the properties of the rubber composites extruded with a 12-screw extruder were compared with those extruded with twin-screw extruder. Various W-EPDM composites for synthetic turf filler and car mat were extruded and injection molded, and 3 main properties of tensile strength, elongation and hardness were investigated to develop economical and proper recipes of the rubber composites.