• Carbon letters
• /
• v.10 no.2
• /
• pp.101-108
• /
• 2009

Various silanes, amino silane, vinyl silane, TESPD, and ZS (TESPD/zinc soap complex), are added into chlorinated isobutylene-isoprene copolymer (CIIR)/hard clay/carbon black (CB) compound and they are investigated with respect to the vulcanization characteristics, the processability, and the mechanical properties. In hard clay/CB filled system, only ZS silane added compound shows both lower Mooney viscosity and extrusion torque while vinyl silane added compound showed only a lower extrusion torque. All the ZS added compounds showed the lowest viscosity among them. The silane added compounds showed an increased modulus. In 'fatigue to failure' count test, the ZS added compound showed superior counts compared to other silane (amino, vinyl, TESPD) added compounds. The mechanical properties were significantly increased when the S2 and ZS were added into CIIR/hard clay/CB compound. The ZS added compounds showed a significant improvement on elongation modulus.

• Carbon letters
• /
• v.10 no.2
• /
• pp.109-113
• /
• 2009

Various silanes, amino silane, vinyl silane, TESPD, and ZS (TESPD/zinc soap complex), are added into chlorinated isobutylene-isoprene copolymer (CIIR)/soft clay/carbon black (CB). The vulcanization characteristics, the processability, and the mechanical properties are measured. In soft clay/CB filled CIIR system, there are no significant changes in Mooney viscosity among compounds. Vinyl silane added compound shows a low extrusion torque. All the silane added compounds shows an increased modulus. The mechanical properties are significantly increased when the S2 is added into CIIR/soft clay/CB compounds.

• Elastomers and Composites
• /
• v.29 no.2
• /
• pp.113-120
• /
• 1994

The vulcanization characteristics, physical and electrical properties have been measured for magnetite-loaded CM compounds containing various concentration of magnetite. Samples of the various concentration of magnetite are characterized by oscillating disk rheometer, mooney viscometer, tensometer and resistance meter. The morphology and dispersion of magnetite are analyzed by scanning electron microscope(SEM). The results obtained are as follows : 1. The CM compound without magnetite shows plain curve, while the CM compounds containing magnetite show short curves. 2. The maximum volume of magnetite is 600 phr in the CM compounds. The magnetite of 30 to 150 phr of magnetite act as reinforcement agents and the 50 phr magnetite shows maximum tensile strength. 3. The electric conductivity is mostly influenced by the conditions of temperature, compacting pressure, and magnetite orientation. Further efforts should be made to develop a new design in various electric conductivity fillers for the most efficient and applicable rubber products.

• Elastomers and Composites
• /
• v.30 no.1
• /
• pp.9-19
• /
• 1995

To make filler loaded conducting rubber which has the excellent electronical and physical properties, CR and NBR were mixed with magnetite$(Fe_3O_4)$. From the result of the study, vulcanization characteristics shows the upgrading curve as increase in filler concentration and CR has more torque than NBR. When elongation be higher, modulus comes to decreases. Tear strength gradually decrease after showing of the maximum point when is in the 100phr in all. Resilience is not good to cause the increase in filler concentration. In the electrical properties, conductivity becomes smaller when filler concentration is increased. The increase of voltage makes an conductivity grown, but the changed rate is weak. The influence of temperature hardly changes on increasing temperature. The morphology and the distribution for a conductivity filler through SEM were better, the more filler concentration increase, the shorter the particle interval is.

• Macromolecular Research
• /
• v.10 no.6
• /
• pp.345-358
• /
• 2002

The electrical conductivity during vulcanization process was measured as a function of time for the system of TiC loaded styrene-butadiene rubber (SBR) composites. The phenomenon of negative and positive temperature coefficients of conductivity and its conduction mechanism were also studied for the SBR polymeric composites. The current-voltage characteristics of the polymeric composites were non-linear in high voltage and showed a switching effect. The effects of temperature on the thermal conductivity and effective dielectric constant were measured. The measured parameters were found to be dependent on TiC concentration. The electromagnetic wave shielding (EMS) of the SBR-TiC polymeric composite was also examined. The SBR filled with TiC could be expected to be promising novel smart polymeric composites for self-electrical heating, temperature sensor, time delay switching, and electro-magnetic wave shielding effectiveness.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.173-185
• /
• 2018

Effects of three different types of dispersions and flow improving additives composed with fatty acid esters, fatty acid metal salts and amide compound on the vulcanization and the mechanical properties properties of rubber compounds of EPDM and carbon black as fillers. were investigated using Mooney viscometer, moving die rheometer, hardness tester, and universal test machine. The aging characteristics of vulcanized EPDM compounds were also investigated. The Mooney viscosity measured at $125^{\circ}C$ showed a tendency to decrease in the order of amide type> metal salt type > ester type additive. Scorch time showed little or no difference with the addition of ester or metal salt type additives, but the amide type additive shortened a scorch time more than one minute. Rheological measurement data obtained at $160^{\circ}C$ showed that the vulcanization time was faster for metal salt type and amide type additive systems. Delta torque values of EPDM compound increased with metal salt type and amide type additives, but slightly decreased with ester type additive. The tensile strength of the EPDM compound was greatly improved when an ester type additive was added, but the amide type or metal salt type additive had no significant effect. The elongation was significantly improved for metal salt type additive, while the rest were not significantly affected. The tear strength of the EPDM compounds increased with the addition of all kinds of additives, and it increased remarkably in the case of metal salt type additive. Hardness of the EPDM compounds was nearly same value regardless of additive types. The thermal aging of the EPDM blend at $100^{\circ}C$ for 24 h showed little change in the case of metal salt type or amide type additive, but the elongation tends to decrease by 10-20% for all EPDM compounds containing additives.

• Journal of the Korean Chemical Society
• /
• v.54 no.6
• /
• pp.749-754
• /
• 2010

In this study, rubber vulcanization property, change in physical property, morphology and chemical characteristics of blended rubber depending on various IR/CR ratio were investigated for the purpose of the improvement of material property and durability. The effect of surface treatment by chlorine on the friction coefficient was also studied with various conditions of surface treatment. In terms of vulcanization property, as the amount of CR content increased, the speed of cure was decreased, while the density of crosslinking stayed constant. It means hardness and modulus were increased as the CR content increased. It is related to change in cure property and mechanical strength was improved by the effect of crystallization reaction. In the aging property, as the CR content increases, the changed amount of basic properties were decreased, which acts as a reducing factor in change of aged property by complementing weak point in mechanical property. It was found that the degree of property change for surface treated samples were reduced. According to the microscopic result, the degree of surface dispersion on rubber blends was increased by increasing CR content. Rubber surface showed uniform direction in pattern with increased smoothness and luster by treatment with chlorine. The degree of rubber reforming was measured by the remaining amount of chlorine and the friction coefficient was dependent on the amount of chlorine combined with rubber. In the initial stage of surface treatment, from 10 to 40 phr, the friction coefficient of specimen was rapidly reduced. However, as the concentration of chlorine solution increased, the change in friction coefficient was decreased.

• Elastomers and Composites
• /
• v.29 no.1
• /
• pp.18-29
• /
• 1994

The purpose of this study is to investigate reinforced effect between silica treated by coupling agents and rubber matrix under the configuration chemical bonds, and the effect of silica particles coated by organic polymers using aluminum chloride as the catalyst. In vulcanization characteristies were tested by Curastometer. The M-series vulcanizates were reached to the fastest optimum cure $time(t_{90})$ and R-series vulcanizates with the same formula had the shorted optimum cure times. Tensile characteristics measuring with a tensile tester revealed that the M-series vulcanizate was the best in the physical properties, such as tensile strength. In 100% modulus, however, the S-series vulcanizates appeared to be better than the other vulcanizates. Also, hardness showed the following order : S-series>R-series>M-series with the order of elongation R-series>M-series>S-series. In SEM test, shapes of chemical treated silicas were observed. The dispersion of filler in the SBR composite appeard uniformly. In RDS test for the dynamic characteristics, G' indicates that S-3 shows the highest value with the next order M-3>R-3, and the order of damping values are as followe: M-3>M-3>R-3.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.377-380
• /
• 2002

Acoustic Characteristics of Nitrile Butadiene Rubber with Carbon Black ContentAcoustic and mechanical properties of Nitrile Butadiene Rubbers (NBR) with the variation of the carbon black content were investigated. NBR where the acrylonitrile content is $33\%$ based on the mole percent has been prepared with fixed sulfur content for vulcanization. Acoustic measurement of the prepared rubbers were peformed in the frequency region of $300\;\~\;1000\;kHz$. Their mechanical properties such as density, hardness were also measured. Increase of the carbon black content in the rubber resulted in enhancement of the mechanical property and linear increase of the sound speed as function of the carbon black content. Interestingly, attenuation of the sound speed was only affected by the existence of the carbon black and not by the amount of carbon black in the experiment range of this article. In this study, it was found that the amount of carbon black content in the NBR was correlated with the acoustic properties and can be estimated nondestructively by the measurement of the specific acoustic property.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.32 no.4
• /
• pp.349-355
• /
• 2019

A fire, be it caused intentionally or unintentionally, leads to economic loss and physical damage, and requires digestion. The number of fires is increasing yearly, and electrical fires account for more than 30% among the main causes of fires. Electric wires that catch fire typically employ silicone coatings; silicone has organic as well as inorganic properties. Silicon is a natural, nonexistent, synthetic product with numerous applications. In this study, a silicon rubber for application in wires was prepared by high-temperature vulcanization (HTV) with a Shore A hardness of 70. We report results for the flame retardancy test and the fire safety characteristics via inorganic analysis. For this, a quartz inorganic material was added to the wire specimen, and 18% powdered extinguishing agent ammonium phosphate and expanded vermiculite respectively. Thus, expanded vermiculite showed the best flame retardancy and fire safety characteristics.