• Composites Research
• /
• v.27 no.3
• /
• pp.115-121
• /
• 2014

The effect of addition of gypsum on the rheology, physico-mechanical properties, thermal properties and morphology development of polymer composites based on polyvinyl chloride (PVC) and waste-gypsum with and without methylene-butadiene-styrene (MBS) has been studied. It was shown that the replacement of gypsum for methylene-butadiene-styrene (MBS) component in PVC/gypsum polymer composites enhanced the tensile strength and stiffness of composites, but gradually decreased its impact strength. The observation of morphology, the results of the physico-mechanical properties and thermal properties proved simultaneously that PVC/gypsum composite with the waste-gypsum content of 22.56 wt% reached the optimum results among five kinds of PVC/gypsum polymer composite materials investigated.

• Korean Journal of Materials Research
• /
• v.17 no.11
• /
• pp.601-605
• /
• 2007

The tribological properties of acrylonitrile-butadiene rubber (NBR) filled with two kinds of carbon black filler were examined. Different types of Semi-Reinforcing Furnace (SRF), and High Abrasion Furnace (HAF) blacks were used as filler material to test the influence of carbon black particle size on the friction and wear of NBR. Results from tribological tests using a ball on disk method showed that the smaller HAF particles were more effective for reducing the wear of NBR during frictional sliding. The hardness, elastic modulus at 100% elongation, and elongation at break were measured to examine the correlation between the effects of carbon black on the mechanical and tribological properties of the NBR specimens. The wear tracks of the NBR specimens were observed with scanning electron microscopy (SEM). The wear tracks for NBR with different ratios of SRF and HAF showed clearly different abrasion patterns. Mechanisms for the friction and wear behavior of NBR with different sizes of carbon black filler were proposed using evidence from wear track observation, as well as the mechanical and tribological test results.

• Applied Chemistry for Engineering
• /
• v.25 no.2
• /
• pp.147-151
• /
• 2014

In many polymer processing operations, the diffusion of small molecules in polymeric materials plays an important role. The fundamental physical property required to design and optimize processing operations is the mutual diffusion coefficient. To investigate the transport properties of polymer/solvent systems at infinite dilution, capillary column inverse gas chromatography (CCIGC) is often employed. In this study, diffusion and partition coefficients of cyclic solvents in styrene/butadiene/styrene (SBS) block copolymer were measured over a wide temperature range using the CCIGC technique.

• Membrane Journal
• /
• v.18 no.3
• /
• pp.256-259
• /
• 2008

In this study, graphite or zeolite 4A was mixed with poly(acrylonitrile-butadiene-strene) (ABS) to make hybrid films, and permeation characteristics of air and water vapor through these films were investigated. In all cases, gas permeabilities of hybrid films were lower than that of pure ABS films. The permeability decrease of oxygen was slightly larger than that of nitrogen, resulting in the little decrease of $O_2/N_2$ selectivity. In addition, the water vapor transfer rates (WVTR) of hybrid films were about half of ABS film's. The decrease of permeabilities may be owing to the increase of tortuosity for diffusion in hybrid films.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.4 s.97
• /
• pp.110-115
• /
• 1999

The surface gloss of an injection molded part is one of the most significant point for evaluating the quality of products appearance. The effects of process condition on the gloss of ABS(Acrylonitrile-Butadiene-Styrene) molded part were investigated in this work. The measurements of gloss and morphology on the surface of molded part were carried out with different melt temperature, mold temperature, mold surface roughness, injection pressure and holding pressure. Gloss had a maximum value with melt temperature in the range of 210 to 220 ${^\circ}C$ and with mold temperature 40 to 50${^\circ}C$ and with injection pressure 80~90 MPa, respectively. Melt temperature was shown to have the largest effect on gloss in our work. Gloss was not improved in the region of melt temperature 240${^\circ}C$ above and of mold temperature 60${^\circ}C$ above. It was concluded that the variation of gloss was mainly caused by rubber particles migration under shear stress not by their aggregation or necklace.

• Applied Chemistry for Engineering
• /
• v.8 no.6
• /
• pp.979-984
• /
• 1997

Test specimens of polymer-cement concrete composites were prepared using styrene-butadiene rubber(SBR) latex, ethylenevinyl acetate(EVA) and polyacrylic ester(PAE) emulsions as polymer dispersions in cement modified system at constant slump($10{\pm}0.5cm$), then compressive and flexural strengths water absorption, pore size distribution, and microstructures were investigated. Compressive and flexural strengths of these composites were remarkably improved with an increase of polymer-cement ratio. These composites had a desirable pore size distribution against frost damage due to a small capillary pore volume. Continuous polymer film was able to form in higher than 15% of polymer cement ratio.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.4
• /
• pp.174-177
• /
• 2010

We have developed an environment-friendly etching process, an alternative to the dichromic acid etching process, as a pretreatment of acrylonitrile-butadiene-styrene (ABS) plastic for electroless plating. In order to plate ABS plastic in an electroless way, there should be fine holes on the surface of the ABS plastic to enhance mechanically the adhesion strength between the plastic surface and the plate. To make these holes, the surface was coated uniformly with dispersed chemical foaming agents in a mixture of environmentally friendly dispersant and solvent by the methods of dipping or direct application. The solvent seeps into just below the surface and distributes the chemical foaming agents uniformly beneath the surface. After drying off the surface, the surface was heated at a temperature well below the glass transition temperature of ABS plastic. By pyrolysis, the chemical foaming agents made fine holes on the surface. In order to discover optimum conditions for the formation of fine holes, the mixing ratio of the solvent, the dispersant and the chemical foaming agent were controlled. After the etching process, the surface was plated with nickel. We tested the adhesion strength between the ABS plastic and nickel plate by the cross-cutting method. The surface morphologies of the ABS plastic before and after the etching process were observed by means of a scanning electron microscope.

• Journal of ILASS-Korea
• /
• v.20 no.4
• /
• pp.207-216
• /
• 2015

Recently, the researches for air pollutant control technologies have been performing in Korea, while considering an one of the latest main topics as problems on air pollutant control. However, it is difficult to investigate emission amount of air pollutant by passenger cars, because of lack of the domestic information about mobile source; the number of research institutes are less in the whole. Especially, the informations on registered numbers and emissions of motorcycles are less. Thus, in this study, the analysis that is based on experimental results was conducted for finding out source profiling and emission characteristics on motorcycles exhaust. For these experiments, the domestic motorcycles were chosen and evaluated by EURO III standard. From the result, controlled pollutants (CO, HC, NOx) were met to EURO III, but low displacement motorcycles showed a higher incomplete combustion reaction than that of 250 cc motorcycles. Additionally, uncontrolled pollutants (BTEX and 1,3-butadiene) were decreased with increasing a displacement of motorcycles. However, the emission trend of aldehydes was not followed that of those; the formaldehyde ratio increased upto approximately 33%, with increasing a displacement of motorcycles. In the future, it would be used to support the CAPSS as basic data of Korea.

• Korean Journal of Materials Research
• /
• v.20 no.2
• /
• pp.104-110
• /
• 2010

The characteristics of all polymer composites containing carbon materials are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape. As a consequence, in this paper we discuss the aspects of the mechanical, electrical and thermal properties of composites with different fillers of carbon black, carbon nanotube (CNT), graphene and graphite and focus on the relationship between factors and properties, as mentioned above. Accordingly, we fabricate rubber composites that contain various carbon materials in carbon black-based and silica based-SBR matrixes with dual phase fillers and use scanning electron microscopy, Raman spectroscopy, a rhometer, an Instron tensile machine, and a thermal conductivity analyzer to evaluate composites' mechanical, fatigue, thermal, and electronic properties. In mechanical properties, hardness and 300%-modulus of graphene-composite are sharply increased in all cases due to the larger specific surface. Also, it has been found that the thermal conductivity of the CNT-composite is higher than that of any of the other composites and that the composite with graphene has the best electrical properties.

• Polymer(Korea)
• /
• v.25 no.2
• /
• pp.233-239
• /
• 2001

The ethylene propylene diene terpolymer (EPDM) blends with acrylonitrile butadiene rubber (NBR) were prepared by mechanical mixing method. Mooney viscosity, cure behaviors, compression set and dynamic mechanical properties were subsequently examined. Dynamic characteristics of the entire blends determined from a Rheovibron generally showed two glass transitions (T'$_{g}$s), -43$^{\circ}C$ and -4$^{\circ}C$ for NBR and EPDM, respectively. The tan $\delta$ peak monotonically shifted toward the higher temperature with increasing NBR content. It was also found that the optimum cure time was significantly decreased with loading of NBR.