• Elastomers and Composites
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• v.42 no.4
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• pp.232-237
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• 2007

We examined the properties of compound and made compound of the optimum state using the properties of each material to evaluate suitability of FKM, VMQ, EPDM, NBR with gasket for fuel cell which is in general use with the material of gasket. It could be found from the compound made with setting the optimum state that NBR is worse than FKM in the chemical property of matter for a long term, and VMQ is worse than FKM in the elution of a metal ion, and EPDM is worse than FKM in the permeability of gas. As a result of leak evaluation of gasket for fuel cell with using FKM, it appeared leak in short time when contracting pressure is getting lower and sealing pressure is getting higher. And as a result of the life prediction with using Arrhenius model, we could predict that it is possible to continuously drive for 60,000 hours.

• Elastomers and Composites
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• v.44 no.2
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• pp.156-163
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• 2009

Our objective is to increase the flowability of Polypropylene(PP) compounds and achieve flow mark free surface in injection molded specimen. We have investigated flowabilities of PP compounds which were composed of PP, rubber, talc, and trace amount of additives. Flowability measurement was performed with four types PPs of which molecular weight distributions(MWD) and melt indexes(MI) were different. Rheological properties of the PP compounding materials, such as spiral flow(SF) length, MI, and shear viscosity, were evaluated. When PP with the broad MWD was used, there were remarkable cases where the spiral flow length of low MI PP compound was longer than that of higher MI PP compound. The PP compound having low MI but broad MWD PP has more flowability than the compound with only high MI.

• Elastomers and Composites
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• v.54 no.4
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• pp.308-312
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• 2019

Polyphenylene sulfide (PPS) is a well-known super engineering plastic with a high melting temperature (above 290℃). It is generally insoluble under regular conditions. Therefore, it can be used for replacing metallic materials. Many researchers are looking at the possibility of replacing aluminum in the engine compartment of an automobile. However, studies on PPS are not common as compared to conventional engineering plastics because only a few companies produce super engineering plastics. In this research, the material properties of PPS composites containing two different kinds of glass fibers and produced under different processing temperatures were investigated. The tensile strength of the PPS composites increased as the processing temperature increased. Although glass fibers with similar aspect ratios were compounded under the same processing condition, one of them yielded a higher mechanical strength.

• Polymer(Korea)
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• v.30 no.3
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• pp.266-270
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• 2006

Poly [(dimethylmethylyinyl) siloxane] phosphineoxide (PMViSPO) was prepared by adding phosphorus oxychloride $(POCl_3)$ to poly (dimethylmethylyinyl) siloxane (PMViS) at $0^{\circ}C$ under nitrogen atmosphere. Cadmium selenide (CdSe) was prepared by reacting cadmium oxide (CdO), tetradecyl-phosphonic acid (TDPA), trioctylphosphine oxide (TOPO) at $300^{\circ}C$, and adding solution of dissolved Se to tributylphosphine (TBP) and trioctylphosphine (TOP) CdSe-poly [(dimethylmethylvinyl) siloxane] phosphine-oxide (CdSe-SPO) adduct was synthesised by adding PMViSPO to CdSe solution. Liquid silicone rubber composite (LSRC-1) was prepared by compounding $\alpha,\omega-vinyl$ poly (dimethylsiloxane) (VPMS), $\alpha,\omega-hydrogen$) poly(dimethylsiloxane) (HPMS), and CdSe under Pt catalyst, and also LSRC-2 was prepared from VPMS, HPMS, and CdSe-SPO using Pt catalyst. It was confirmed that CdSe nanoparticles with photoluminescence characteristics was dispersed uniformly in LSR matrix. The diameter of CdSe was $30\sim50nm$. By measuring the number of CdSe nanoparticles, 202 particles of CdSe in LSRC-2 and 165 particles of CdSe in LSRC-1 were dispersed in the same area of LSR matrix. Thermal stability for LSRC-2 compounded with CdSe-SPO was better than LSRC-1.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.1
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• pp.68-80
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• 2006

This study aimed to prepare the fundamental data and assess the status and trend of exposure level for 5 chemical substances such as sulfuric acid, hydrogen chloride, ammonia, formaldehyde and phenol in manufacturing industry by type of industry, working process, and size of factory, chronological change. Subjects related to this study consist of 146 factories, 12 industries and 17 working processes located in Busan area from Jan. 1997 to Dec. 2001. 1. All 5 kinds of chemical substances by type of industry, working process were generated in chemical manufacturing industry. There were founded in 8 types of industries and 13 types of working processes for ammonia, which is the highest number of in all 5 chemical substances. 2. In terms of the exposure level for 5 chemical substances by type of industry, working process, geometric mean concentration for sulfuric acid was $0.40mg/m^3$ in manufacture of chemicals and chemical products, $0.30mg/m^3$ in compounding process, for hydrogen chloride was 0.57 ppm in manufacture of basic metal, 0.48 ppm in dyeing process, for ammonia was 1.11 ppm in manufacture of rubber and plastic products, 0.94 ppm in buffing process, for formaldehyde was 0.49 ppm in manufacture of wood and of products of wood and cork, except furniture; manufacture of articles straw and plating materials, 0.53 ppm in mixing process, and for phenol were 0.53 ppm in manufacture of chemical and chemical products, 0.55 ppm in compounding process, respectively. Results for 5 chemical substances by type of industry and working process were significantly higher than those of the others(p<0.05). 3. The exposure level for hydrogen chloride, formaldehyde were significantly increased by size of industry (p<0.01). ammonia was significantly decreased by size of industry (p<0.01). 4. In trend of the concentration difference of five chemical substances by chronology, geometric mean concentration for sulfuric acid was significantly increased (p<0.01), hydrogen chloride and ammonia were significantly decreased by year (p<0.05) and for formaldehyde and phenol were decreased in chronological change. According to the above results 5 chemical substances were founded together in a way mixed in the same places one another and concentrations of chemical substances by industry, working process, size of industry and year appeared markedly. The authors recommend more systemic and effective work environmental management should be conducted in workplaces generating five chemical substances.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.9-13
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• 2014

Glass fiber reinforced thermoplastics(GFRTP) is made by adding chemical additive to glass fabric which is strong at a high temperate, incorrodible, and good at intensity and specific gravity. Although we focused on the weight lightening, the intensity of GFRTP is also important. To remedy thermoplastic resin's inferior property of matter to thermo-hardening resin, we formed several specimen, differing the chemical additive as Homo PP, MAPP 3%, Rubber 5%, and mixed. We put pressure of 5 type on the specimens. The analyses result for the different pressure, the resin spreads evenly, then the coherence is increased. Eventually, the mechanical properties are changed. When high intensity is needed, it is good idea to use polypropylene(PP) which has good coherence with glass fabric as chemical additive. We can get better intensity when we form the resin at the optimum pressure depending on mixing of chemical additive and glass fabric than when we increase the pressure.

• Elastomers and Composites
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• v.48 no.2
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• pp.125-132
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• 2013

In this work, we have discussed new engineering systems for preparing carbon master batch composed by carbon black and various organic compounds. In general, polymer resin, which applied for automobile tire, household items, and various industry items, is used with the fillers including carbon black and silica to control the color or properties. Domestic part and material industry has been remarkably developed in that the development of materials including the compounding of raw materials. Meanwhile, the engineering technique for mass production has not reached to a requirement of industry due to slow technique development and high dependence on foreign. Thus, we will focus on the introduction of new engineering technique developed by domestic company for preparing carbon master batch.

• Elastomers and Composites
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• v.47 no.3
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• pp.231-237
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• 2012

This study measured the mechanical and damping properties of EPDM compounds including fillers. Semi-reinforcing furnace black (SRF), high abrasion furnace black (HAF) and acetylene black were used as fillers. Dicumyl peroxide (DCP) were used as curing agents. The measurements were conducted using a moving die rheometer (MDR), durometer, universal testing machine (UTM), compression set and dynamic mechanical analysis (DMA). The tensile strength and elongation at break increased with increasing SRF contents in EPDM compounds. However, they decreased with increasing the amount of acetylene black. In the inspecting temperature range, EPDM compound filled acetylene black had stable storage modulus. Furthermore, the tan ${\delta}$ of the EPDM compounds obtained was enhanced by compounding with acetylene black.

• Elastomers and Composites
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• v.48 no.1
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• pp.18-23
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• 2013

Nylon 12 elastomer was slightly crosslinked in molten state by the addition of small amount of dicumyl peroxide (DCP) as a crosslink agent and triallycyanuate (TAC) as a co-agent during melt compounding at $160^{\circ}C$ in an internal mixer. The effect of the peroxide crosslinking on mechanical, dynamic mechanical and rheological properties of the nylon 12 elastomer was investigated by means of tensile testing, dynamic mechanical analysis (DMA) and small amplitude oscillating rheometer, respectively. With modification, there is an improvement in tensile modulus and Young's modulus with decease in elongation at break. DMA results for peroxide modified nylon 12 elastomers demonstrated that the glass transiaiton temperature of PTMG segment shifted to higher temperature and the storage modulus remained constant above the melting temperature of nylon 12 segments. Melt rheological studies revealed that the peroxide modified nylon 12 elastomer exhibited a more solid like behavior and stronger shear thinning behavior compared to neat nylon 12 elastomer, which was more prominent at higher TAC content in the polymer matrix. The peroxide modified nylon 12 elastomer exhibited good elastic recoverability and improved mechanical properties without sacrificing melt processibilty, and especially the service temperature range increased as compared to neat nylon 12 elastomer.

• Polymer(Korea)
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• v.28 no.2
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• pp.143-148
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• 2004

${\alpha}$,$\omega$-Hydrogen polyorganosiloxane(HPMDMS) prepolymer was prepared from equilibrium polymerization ofoctamethylcyclotetrasiloxane, 1,3,5-trimethylcyclotrisiloxane, 1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane, and 1,1,3,3-tetramethyl disiloxane as an end-blocker in the presence of tetramethylammonium siloxanolate as a catalyst. Polyorganosiloxane modified with dimethylacrylamide(APMDMS) was prepared by hydrosilylation of HPMDMS with dimethylacrylamide in the presence of Pt catalyst, and followed by coordination of metal oxide (APMDMS-MO), such as NiO and FeO, to the amide moieties of the resulting polymer. The chemical structures of HPMDMS and APMDMS were confirmed by FT-IR and $^1$H-NMR analysis. Liquid silicone rubber containing metal oxide composite (LSRMO) was prepared by compounding APMDMS-MO, ${\alpha}$,$\omega$-vinylpolydimethylsiloxane, and a catalyst in a high speed dissolver. The thermal conductivity of LSRMO composite was determined to be 0.29 W/mK, and the volume resistivity exhibited a lower value than that of LSR composite. The mechanical and thermal properties of LSRMO and LSR composite were measured by UTM and TGA.