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Effect of 1,3-Diphenyl-guanidine (DPG) Mixing Step on the Properties of SSBR-silica Compounds

  • Lim, Seok-Hwan;Lee, Sangdae;Lee, Noori;Ahn, Byeong Kyu;Park, Nam;Kim, Wonho
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.81-92
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    • 2016
  • 1,3-Diphenylguanidine (DPG) is commonly used as a secondary accelerator which not only acts as booster of cure but also activating silanization reaction. The aim of this study is to increase the interaction between silica and rubber by using DPG. In this study, mixing was proceeded in two steps. The T-1 compound is mixed DPG with silica and silane coupling agent in the kneader at high temperature which is named as $1^{st}$ mixing step. T-3 compound is mixed DPG with curatives in the two-roll mill at low temperature which is named as $2^{nd}$ mixing step. The T-2 compound is mixed a half of DPG in $1^{st}$ mixing step and the remainder is mixed in $2^{nd}$ mixing step. Total DPG content was equal for all compounds. When DPG is mixed with silica, silane coupling agent during the $1^{st}$ mixing step, a decrease in cure rate and an increase in scorch time can be seen. This indicates that DPG is adsorbed on the surface of silica. during rubber processing. However, bound rubber content is increased and dynamic properties are improved. These results are due to the highly accelerated silanization reaction. However, there are no significant difference in 100%, 300% modulus.

A Sduty on the Vulcanization Characteristic of Combined Accelerators in SBR compounds. (SBR의 가황촉진제(加黃促進劑) 병용효과(倂用效果)에 의한 가황특성(加黃特性) 연구(硏究))

  • Choi, Jae-Woon;Lee, Ki-Jong
    • Elastomers and Composites
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    • v.17 no.3
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    • pp.151-158
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    • 1982
  • The purpose of this study is to get comparitive results on the combined accelerator systems comprised of MBT, MBTS, DPG and CBS with TMTD, TMTM, Zn-MDC and DPG to SBR compound. Vulcanization characterstics and physical properties of the combined accelerators have been studied by mean of the Mooney viscometer, tensile testing machine, aging chamber and so on. According to the test results, TMTD with DPG system has shown faster Mooney scorch time than other system. The vulcanizate comprise of Zn-MDC with DPG and TMTD with DPG accelerator system has taken advantage of heat resistance.

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Effect of Acrylonitrile-Butadiene Rubber on the Properties of Silica-Filled Styrene-Butadiene Rubber Compounds: Reduction of Silane Coupling Agent and Diphenylguanidine (실리카로 보강된 SBR 배합물의 특성에 미치는 NBR 효과: 실란커플링제와 DPG의 사용량 감소)

  • Choi, Sung-Seen;Chang, Dong-Ho;Kim, Ik-Sik
    • Elastomers and Composites
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    • v.37 no.4
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    • pp.217-223
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    • 2002
  • Silica-filled rubber compounds show poor filler dispersion and slow cure characteristics compared to carbon black-filled ones. In general, a silica-filled rubber compound contains silane coupling agent (bis-(3-(triethoxysilyl)-propyl)-tetrasulfide, TESPT) and diphenylguanidine (DPG) to improve the filler dispersion and to make fast cure characteristics. Acrylonitrile-butadiene rubber (NBR) improves the filler dispersion in silica-filled styrene-butadiene rubber (SBR) compounds. In this study, effect of NBR on the properties of silica-filled SBR compounds was investigated. Properties of the compounds which contain NBR without DPG or with small amount of TESPT (Compound A) were compared with those of the compounds which contain TESPT and DPG without NBR (Compound B). Scorch time of Compound A is faster than those of Compound B. Modulus and tensile strength of Comound A are slightly lower than those of Compound B. Traction property of the Comound A is better than that of the Compound B. Addition of NBR leads to reduction of the used amount of TESPT and DPG.

FURTHER PURIFIED GINSENG EXTRACT FRACTION (D-O-ANA) FOR INSULIN RELEASE AND ITS MODE OF ACTION COMPARED WITH THE ISOLATED RESIDUAL COMPONENTS (인삼성분 D-O-ANa이 인슐린 분비에 미치는 영향 및 작용기전에 관한연구)

  • KIMURA Masayasu;SUZUKI Jun;WAKI Isami;KIMURA Ikuko;TANAKA Osamu;MATSU-URA Hiromichi
    • Proceedings of the Ginseng society Conference
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    • pp.191-197
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    • 1984
  • A further purified fraction (D-O-ANa) was obtained from DPG 3-2 fraction of Ginseng Radix by complete removal of saponins, nucleosides, nucleic acid bases, amino acids, and sugars. D-O-ANa - induced insulin release was investigated to compare with that of DPG 3-2 and other isolated components. Among the sub fractions of DPG 3-2, D-O-ANa exhibited the most potent release of insulin with or without high concentrations of glucose, and it particularly enhanced the second phase of glucose-induced insulin release. DGP 3-2 potentiated significantly the glucose-induced insulin release from the isolated islets of diabetic mice at increasing concentrations of extracellular calcium ions (0.16 - 2.5 mM). A definite relationship was found between calcium $(^{45}Ca)$ uptake and insulin release. Ginsenoside $(G)-Rb_1\;and\;G-Rg_1$ did not enhance the glucose-induced insulin release. The effect of ginseng saponins was blocked by glucose (16.7 mM), being distinctly different from the glucose-potentiated effect of DPG 3-2. The insulin release effect of $G-Rg_1$ was unaffected by the presence or absence of extracellular $Ca^{2+}$ and theophylline. Adenosine also increased insulin release from isolated islets, but had no effect on perfused rat pancreas. Arginine stimulated insulin release less evidently than D-O-ANa, though arginineand adenosine-induced glucagon releases were more remarkable. In conclusion, D-O-ANa appears to be a major fraction in insulin release activity of ginseng and its mode of action may be related to $Ca^{2+}$ ion uptake. This physiological mechanism was distinct from that of the abnormal release induced by ginseng saponins.

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Studies on Synthesis of Liquid Polyester Polyol by using DMT(Dimethylterephthalate) and NDC(Dimethyl-2,6-Naphthalene Dicarboxylate) (DMT(Dimethylterephthalate), NDC(Dimethy1-2,6-Naphthalene Dicarboxylate)를 이용한 액상 폴리에스터 폴리올의 합성에 관한 연구)

  • Kim, Sang-Hern
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.3
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    • pp.317-327
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    • 2009
  • In this study DMT(Dimethylterephthalate), NDC(Dimethyl-2, 6-Naphthalene Dicarboxylate) were used to synthesize polyester polyol which shows enhanced storage stability, improved flame retardancy, and good compressive strength. If DMT and NDC react respectively with DEG(Diethylene Glycol) which is kind of linear diol, the obtained polyester polyols tend to crystallize easily after the reaction. In case of DMT, PA(Phthalic Anhydride) which has asymmetric structure was introduced to retard the crystallization. In case of NDC, DPG(Dipropylene Glycol) which has an methyl side chain was introduced to prevent the crystallization. It was found that to introduce DPG was much more effective method to prevent the crystallization than PA. NDC and DMT were reacted together with DPG for various compositions of NDC:DMT(8:2, 6:4, 4:6 mol ratio). The obtained NDC-DMT-DPG based polyester polyol showed improved flame retardancy, and good compressive strength with increasing the content of NDC.

A Sduty on the Vulcanization Characteristic of Combined Accelerators in SBR Compounds ( II ) (SBR의 가황촉진제(加黃促進劑) 병용효과(倂用效果)에 의한 가황특성(加黃特性) 연구(硏究) ( II ))

  • Choi, Jae-Woon
    • Elastomers and Composites
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    • v.17 no.4
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    • pp.215-225
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    • 1982
  • The purpose of this study is to get comparitive results on the combined accelerator systems comprised of MBT, MBTS, DPG and CBS with TMTD, TMTM and Zn-MDC to SBR compound. Vulcanization characterstics and physical properties of the combined accelerators have been studied by means of the Mooney viscometer, the Monsanto disc rheometer, tensile testing machine, aging chamber and so on. According to the test results, DPG, MBT and Zn-MDC system have show faster Mooney scorch time and optimum cure time than other systems. The Vulcanizate comprise of DPG, MBT and TMTD accelerator system has taken adventage of tensile strength, elongation, 100% modulus, resilience, compresion set.

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Effect of Hypobaric Hypoxia on Levels of Reduced Glutathione and 2,3-Diphosphoglycerate in Rabbit Red Blood Cells (저기압(低氣壓)이 가토적혈구(家兎赤血球) GSH 및 2, 3-DPG에 미치는 영향에 대하여)

  • Yu, Chang-Jun;Agar, N.S.;Webster, M.E.D.;Stacy, R.
    • Korean Journal of Veterinary Research
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    • v.22 no.1
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    • pp.9-13
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    • 1982
  • 저기압(低氣壓)이 가토(家兎)의 적혈구(赤血球)용적, 혈색소(血色素)농도, 적혈구수(赤血球數), 적혈구(赤血球) GSH 및 DPG에 끼치는 영향에 대(對)하여 연구 하였다. 적혈구(赤血球) DPG만 제외하고 모든 관찰수치는 증가(增加)되었다.

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A Proposal of the Directed Product Graph and Its Applications to Network Analysis (I) (방향성 적선도의 제안과 회로망 해석에의 응용 (I))

  • 전선미;김수중
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.21 no.2
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    • pp.19-23
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    • 1984
  • A new directed product graph(DPG) is proposed from the product graph for electrical networks. By introducing the direction of an dege and the concept of a loop to product graph, it is more easy and rapid to obtain topologically the denominator of Mason's formula without relation of the sign rule and without arising terms cancelled. Also the constraints of tree selection at a given network-graph can be removed.

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A Study on the Load Balancing Algorithm using Unit Sub-block for Distributed Volume Rendering (분산 볼륨 렌더링에서 단위 서브-블록을 이용한 로드 밸런싱 알고리즘에 대한 연구)

  • Kim, Dae-Hyun;Kim, Tai-Yun
    • Journal of the Korea Computer Graphics Society
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    • v.1 no.2
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    • pp.213-225
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    • 1995
  • 3 차원 볼륨 데이터를 시각화(visualization)하기 위해서는 많은 계산 량과 메모리 량을 필요로 한다. 단일컴퓨터에서 순차 알고리즘을 이용하여 데이터를 시각화하고 분석하는 것은 실시간 응용 프로그램에는 부적합하다. 기존의 병렬 볼륨 렌더링에서의 데이터 분할 방법은 대부분 정적 로드 밸런싱(static load balancing)에 기반하고 있다. 동적 로드 밸런싱에 기반한 기존의 방법들은 불륨 데이터의 정규성(regularity)을 이용할 수 없다는 단점이 있다. 본 연구에서는 3 차원 볼륨 데이터에 대하여 로컬 태스크 큐(local task queue) 기법에 기반한 새로운 로드밸런싱 알고리즘을 제안한다. 제안한 방법은 계산에 참여할 노드(node)들을 PVM(parallel virtual machine)의 동적 프로세스 그룹(dynamic process group: DPG)을 이용하여 정적으로 그룹화(grouping)한다. 각각의 DPG들은 로컬 태스크 큐를 기반으로 단위 서브-블록에 대하여 동적 로드 밸런싱을 수행한다. 최적화된 레이 캐스팅 알고리즘들을 분산 환경에 새롭게 적용함으로써 로드 밸런싱으로 생길 수 있는 오버 헤드를 최소화하였다.

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Carboxylated Nitrile Elastomer/Filler Nanocomposite: Effect of Silica Nanofiller in Thermal, Dynamic Mechanical Behavior, and Interfacial Adhesion

  • Mahaling R. N.;Jana G. K.;Das C. K.;Jeong, H.;Ha C. S.
    • Macromolecular Research
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    • v.13 no.4
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    • pp.306-313
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    • 2005
  • Surface modified nanofillers are often used as curative-cum reinforcing agents for functional polymers. The polymer nanofiller interaction depends on the curative systems used. In the present study the carboxylic group of the carboxylated nitrile elastomer participated in the reaction with Zn-ion coated nanosilica filler producing a type of ionomeric elastomer. The interaction at the molecular level thus produced a high modulus vulcanizate. In this case, the S and MBT system, as curative, had an edge over the MDA and DPG curative system. Interfacial adhesion was enhanced in the presence of Zn-ion-coated nanosilica filler associated with dynamic mechanical behavior. The inferior properties obtained in the case of the MDA and DPG curative system were due to the decreased reactivity of the silica surface, thus reducing interfacial adhesion.