• Elastomers and Composites
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• 제26권4호
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• pp.287-295
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• 1991

The mixing process with carbon black is important in the rubber industries. However, it is difficult to characterize the mixing mechanism of the carbon black. The mixing mechanism(distributive mixing and dispersive mixing) was discribed in this paper. The effect of fill factor on the mixing of the carbon black was studied. The dispersive mixing ability increases with increasing fill factor. However, the distributive mixing ability decreases with increasing fill factor. The effect of the carbon black content on the rheological property of the material was studied in this paper. The viscosity of the material increases with increasing the carbon black content. However, the elasticity of the matarial decreases with the carbon black content.

• Macromolecular Research
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• 제8권4호
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• pp.192-198
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• 2000

Cure characteristics and physical properties of carbon black-filled natural rubber (NR) compounds depending on the mixing procedure were studied using the compounds with different pre-final mixing (FM-1) stages. Carbon master batch (MB) and first and second remitting (1RM and 2RM) stages were employed as the FM-1 stage. Bound rubber content of the FM compound decreased with increasing the mixing steps. This was due to the decrease of the molecular weight distribution of the polymer by the rubber chain scission during the mixing. The Mooney viscosity decreased with increasing the mixing steps. Cure characteristics of the compounds were found to be different with the mixing procedures. The cure times of the compound became slower by increasing the number of the mixing steps. This was explained by the length of rubber chain, the carbon black network, distribution of the curatives in the compound, and immobilization of the polymeric segments. Modulus and tensile strength of the vulcanizate did not show a specific trend with the mixing procedure. Fatigue life of the vulcanizate increased by increasing the mixing stages.

• Elastomers and Composites
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• 제37권1호
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• pp.14-20
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• 2002

실리카로 보강된 고무 배합물은 보강제의 분산이 나쁘기 때문에 카본 블랙으로 보강된 배합물에 비해 더 긴 배합 시간이 필요하다. 실리카와 카본 블랙으로 보강된 천연 고무 배합물에서 배합 공정이 물성에 미치는 영향을 연구하였다. 마스터뱃치(MB) 배합물의 최종 온도를 $150^{\circ}C$로 하였을 때, 실리카와 카본 블랙을 따로 투입하는 경우가 함께 투입하는 공정보다 배합 시간을 더 길게 가질 수 있었다. 실리카를 먼저 투입하는 것이 카본 블랙을 먼저 투입하는 것보다 배합 시간이 길었다. MB 배합 공정을 한 단계로 구성한 배합물과 두단계로 구성한 배합물을 비교하였다. 두 단계 공정으로 배합한 배합물의 스코치 시간이 한 단계 공정으로 만든 배합물의 스코치 시간보다 길었고 bound rubber 함량은 작았다. 두단계 공정으로 만든 가황물은 한단계 공정으로 만든 것에 비해 신율이 높고 인장 강도도 강하고 피로 특성도 우수한 것으로 나타났다.

• 공업화학
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• 제9권7호
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• pp.1065-1069
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• 1998

리튬이온 이차전지에 사용되는 탄소부극의 성능을 향상시키기 위하여 결정성계 탄소재료와 비결정성계 탄소재료의 혼합비율에 따른 조합형 탄소전극을 제조하였으며, 이들의 전기화학적 특성과 충방전 특성을 조사하여 조합비율에 따른 리튬의 삽입과 탈삽입 반응기구 및 최적의 조합조건을 찾고자 하였다. 탄소전극은 결정성계 탄소재료인 natural graphite와 $700^{\circ}C$에서 1시간 동안 열처리된 비결정성계 탄소재료인 petroleum cokes를 사용하였다. 조합비에 따라 제조된 조합형 탄소전극은 두 가지 형태의 탄소재료가 갖는 전극특성을 지니며 50:50wt%로 조합하였을 때 가장 우수한 전기화학적 특성과 충 방전 특성을 나타냈다.

• 환경위생공학
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• 제14권3호
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• pp.31-38
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• 1999

The purpose of this study were to determine the optimum mixing ratio of sewage sludge and papermill sludge as carbon source required to SRB in treating abandoned mine drainage with natural purification wetland. If mixing sewage sludge/papermill sludge 2.0 SO42- reduced 46.2%, and then 30% in mixing ratio 0.5.Because sewage sludge was faster biodegradability than papermill sludge, effluent SCOD was 40mg/L in mixing ratio 0.5, and after that was all but regular. pH and ORP were almost neutral and -160mV, but after that was all but regular and it indicated that SRB activity was suitable. Fe removal rate was 60% in mixing ratio 2.0, and 54% in mixing ratio 0.5. In point of carbon source supply, It indicated that mixing ration 0.5 was considered as the most appropriate, because degradability of swewage sludge under short time was higher than that of papermill sludge.

• Carbon letters
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• 제15권2호
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• pp.117-124
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• 2014

Conductive polymer composites (CPCs) consist of a polymeric matrix and a conductive filler, for example, carbon black, carbon fibers, graphite or carbon nanotubes (CNTs). The critical amount of the electrically conductive filler necessary to build up a continuous conductive network, and accordingly, to make the material conductive; is referred to as the percolation threshold. From technical and economical viewpoints, it is desirable to decrease the conductive-filler percolation-threshold as much as possible. In this study, we investigated the effect of polymer/conductive-filler interactions, as well as the processing and morphological development of low-percolation-threshold (${\Phi}c$) conductive-polymer composites. The aim of the study was to produce conductive composites containing less multi-walled CNTs (MWCNTs) than required for pure polypropylene (PP) through two approaches: one using various mixing methods and the other using immiscible polymer blends. Variants of the conductive PP composite filled with MWCNT was prepared by dry mixing, melt mixing, mechanofusion, and compression molding. The percolation threshold (${\Phi}c$) of the MWCNT-PP composites was most successfully lowered using the mechanofusion process than with any other mixing method (2-5 wt%). The mechanofusion process was found to enhance formation of a percolation network structure, and to ensure a more uniform state of dispersion in the CPCs. The immiscible-polymer blends were prepared by melt mixing (internal mixer) poly(vinylidene fluoride) (PVDF, PP/PVDF, volume ratio 1:1) filled with MWCNT.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.97-103
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• 1999

The power curve during rubber mixing presents useful information for the understanding of rubber mixing process, because the power curve is determined the mixing state of rubber at the point. The time to the second peak on the power curve is known as carbon black incorporation time, BIT. This study gets the quantity relationship of BIT and viscosity of natural rubber, so by determining the mixing time of the compound on the ground of viscosity of the raw rubber. The mixing with natural rubber and carbon black is examined for various grade natural rubbers, encompassing a wide range of Mooney viscosity. Alter smoothing the mixing power curve using a polynomial, the carbon black incorporation time, BIT, was determined time to second power peak on the curve, The BIT's versus specific values on Mooney viscometer test curve show a linear relation, Especially, the peak of initial maximum torque on Mooney viscometer curve, PMT, is most relevant property relating to the BIT. PMT is useful index for determined optimum mixing time, To apply this results at the mixing, we effectively control the natural rubber mixing but can also know the grading of natural rubber upon processability.

• 한국기계가공학회지
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• 제16권5호
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• pp.157-165
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• 2017

The high-pressure resin transfer molding (HP-RTM) technology has been commercialized for fast production of fiber reinforced composite materials. The high-pressure mixing head was one of the most core component of the HP-RTM process. In this study, a mixing head was systematically designed, manufactured and evaluated. This mixing head was composed of a nozzle, a mixing chamber, a cleaning piston part, and an internal mold release part. In actual, a straight-type structure was newly designed instead of the conventional L-type structure for improving the maximum mixing pressure and mixing ratio precision. The performance of mixing head was showed maximum mixing pressure of 15.22MPa and mixing ratio precision of 0.12%. CFRP molding experiments were successfully obtained a 6~11 laminating carbon sheet using HP-RTM presses and specimen molds.

• Carbon letters
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• 제14권4호
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• pp.197-205
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• 2013

Five vapor-grown carbon nanofiber (VGCNF) reinforced vinyl ester (VE) nanocomposite configurations were fabricated, imaged, and mechanically tested in order to obtain information on the influence and the interactions of the role of the microstructure at lower length scales on the observed continuum level properties/response. Three independent variables (the nanofiber weight fraction and two types of nanofiber mixing techniques) were chosen to be varied from low, middle, and high values at equally spaced intervals. Multiple mixing techniques were studied to gain insight into the effect of mixing on the VGCNF dispersion within the VE matrix. The point count method was used for both lower length-scale imaging techniques to provide quantitative approximations of the magnitude and the distribution of such lower length-scale features. Finally, an inverse relationship was shown to exist between the stiffness and strength properties of the resulting nanocomposites under uniaxial quasistatic compression loading.

• 한국재료학회지
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• 제28권11호
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• pp.615-619
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• 2018

To produce carbon electrodes for use in perovskite solar cells, electrode samples are prepared by mixing various weight ratios of 35 nm nano carbon(NC) and $1{\mu}m$ graphite flakes(GF), GF/(NC+GF) = 0, 0.5, 0.7, and 1, in chlorobenzene(CB) solvent with a $ZrO_2$ binder. The carbon electrodes are fabricated as glass/FTO/carbon electrode devices for microstructure characterization using transmission electron microscopy, optical microscopy, and a field emission scanning electron microscopy. The electrical characterization is performed with a four-point probe and a multi tester. The microstructure characterization shows that an electrode with excellent attachment to the substrate and no surface cracks at weight ratios above 0.5. The electrical characterization results show that the sheet resistance is <$70{\Omega}/sq$ and the interface resistance is <$70{\Omega}$ at weight ratios of 0.5 and 0.7. Therefore, a carbon paste electrode with microstructure and electrical properties similar to those of commercial carbon electrodes is proposed with an appropriate mixing ratio of NC and GF containing a CB solvent and $ZrO_2$.