• Title/Summary/Keyword: matrix modifier

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Linear viscoelastic behavior of acrylonitrile-butadiene-styrene(ABS) polymers in the melt: Interpretation of data with a linear viscoelastic model of matrix/core-shell modifier polymer blends

  • Park, Joong-Hwan;Ryu, Jong-Hoon;Kim, Sang-Yong
    • Korea-Australia Rheology Journal
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    • v.12 no.2
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    • pp.135-141
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    • 2000
  • The linear viscoelastic behavior of acrylonitrile-butadiene-styrene (ABS) polymers with different rubber content has been investigated in the frame of a linear viscoelastic model, which takes into account the inter-connectivity of the dispersed rubber particles. The model developed in our previous work has been shown to properly predict the low frequency plateau for the storage modulus, which is generally observed in polymer blends containing core-shell-type impact modifiers. In the present study, further experiments have been carried out on ABS polymers with different rubber content to verify the validity of our linear viscoelastic model. It has been found that our model describes quite properly the rheological behavior of ABS polymers with different rubber content, especially at low frequencies. The experimental data confirm that our model describes the rheological properties of rubber-modified thermoplastic polymers with strong adhesion at the particle/matrix interface more accurately than the Palierne model.

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X-Ray Diffractometric Study on Modification Mechanism of Matrixes for Electrothermal AAS Determination of Volatile Lead and Bismuth

  • Kim, Yeong Sang;Choe, Jong Mun
    • Bulletin of the Korean Chemical Society
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    • v.21 no.1
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    • pp.56-60
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    • 2000
  • The mechanism of a matrix modification for the trace determination of volatile lead and bismuth by an electro-thermal atomic absorption spectrophotometry was studied by a X-ray diffractometry (XRD). For the investigation of structures, the ash products of the elements were produced by using a palladium as a matrix modifier with or without aluminum or nickel as an auxiliary modifier. The same charring conditions as in the analysis of samples were applied together with much concentrated solution of analytical elements and modifiers in a graphite furnace to get a large amount of the product for XRD. The XRD patterns showed PbPd3 for lead and BiPd3 for bismuth. These mean that the reaction procedures through the charring and atomization were changed from $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}$$Pb^0$ to $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}PbPd_3$ ${\rightarrow}$ Pb o for lead and from $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ Bi o to $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ $BiPd_3$ ${\rightarrow}$ $Bi^0$ for bismuth by the addition of modifiers. The volatile elements were stabilized by the formation of palladium alloys through a charring process. Charring temperatures were raised about 500 $^{\circ}C$ by the alloying and the atomization was also stabilized for the enhancement of sensitivities.

Study on miscibility, morphology, thermal and mechanical properties of elastomeric impact modifier reinforced Poly(lactide)/Cellulose ester blends (충격보강제로 강인화된 PLA와 cellulose ester 블렌드의 상용성 및 모폴로지, 열적, 기계적 특성에 관한 연구)

  • Park, Jun-Seo;Nam, Byeong-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4081-4086
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    • 2014
  • Cellulose acetate butyrate (CAB) is a biodegradable resin with excellent optical properties, but it is difficult to apply film process. In this study, an attempt was made to improve the processability of CAB using polyactic acid and the mechanical properties using an impact modifier. Polylacitc acid (PLA)/Cellulose acetate butyrate (CAB) blends with an impact modifier were prepared using a twin screw extruder. The temperature range was $140^{\circ}C$ to $200^{\circ}C$, and the screw speed was fixed to 200 rpm. To evaluate the miscibility of impact modified CAB/PLA, the glass transition behavior and morphology were observed by DSC and FE-SEM. The mechanical properties were investigated by dynamic mechanical analysis (DMA) and a Universal Testing Machine (UTM). In addition, the effect of an impact modifier in the polymer matrix was determined using a notched Izod impact strength tester. Finally, the PLA/CAB/impact modifier 75/25/10 ratio was found to be a compatible system. In the 10wt.% impact modifier, the sample had a 4 times higher izod impact strength than the non-toughening composition.

Characteristics of EVA-Polymer Modified Mortars Recycling Rapid-chilled Steel Slag Fine Aggregate (급냉 제강슬래그를 재활용한 EVA-폴리머 시멘트 모르타르의 특성)

  • Hwang, Eui-Hwan;Kim, Jin-Man
    • Applied Chemistry for Engineering
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    • v.19 no.6
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    • pp.652-660
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    • 2008
  • For the recycling of rapid-chilled steel slag, the mechanical strengths and physical properties of EVA-polymer modified mortars with the various replacement ratios of rapid-chilled steel slag were investigated. Twenty five specimens of polymer modified mortars were prepared with the five different amounts of EVA-polymer modifier (0, 5, 10, 15, 20 wt%) and rapid-chilled steel slag (0, 25, 50, 75, 100 wt%). For the investigation of the characteristics of polymer modified mortars, the measurements such as water-cement ratio, unit volume weight, air content for fresh mortar and compressive strength, flexural strength, water absorption, hot water resistance, porosity and SEM investigation for curing specimens were conducted. As a results, with an increase in the replacement ratio of rapid-chilled steel slag, water-cement ratios decreased but unit volume weight increased remarkably. With increasing EVA-polymer modifier and the replacement ratio of rapid-chilled steel slag, percent of water absorption decreased but compressive and flexural strengths increased remarkably. By the hot water resistance test, mechanical strengths decreased but total pore volume and porosity increased remarkably. In the SEM observation, the components of specimen were shown to stick to each other in the form of co-matrix phase before hot water resistance test, but polymer modifier of co-matrix phase was decomposed or deteriorated after hot water resistance test.

Direct Determination Method of Antimony in High Purity Copper Metal by Graphite Furnace Atomic Absorption Spectrometry (흑연로 원자 흡수흡광법에 의한 고순도 구리 합금중의 안티몬의 직접 분석 방법)

  • Yoo, K.S;Kyung, J.D;Kwon, J.G;Lee, J.J
    • Journal of the Korean Chemical Society
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    • v.39 no.4
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    • pp.252-256
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    • 1995
  • A study was carried out for the development of direct determination of antimony in high purity copper metal without preseparation. The large excess of copper seemed to be performed as the matrix modifier to enhance the absorbance of antimony in copper metal. Sensitivity enhancement of Sb was obtained at the condition of the ashing temperature of $600^{\circ}C(20s){\sim}700^{\circ}C(10s)$ rather than $1000^{\circ}C(20s){\sim}1100^{\circ}C(10s)$, and the atomization temperature of $2200^{\circ}C.$ The operating pressure of argon gas was readjusted to the optimum condition at 2.0 kg/$cm^2.$ The linearity of the Sb calibration graph could be obtained in the range of 20 ppb up to 200 ppb Sb in existence of 5,000 ppm Cu with the coefficient of variation of about 5%.

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Analysis of Lead in Blood using SR(self-reversal) and $D_2$ Arc Background Correction Methods (SR 바탕보정법과 $D_2$ 바탕보정법에 의한 혈액 중 Pb 분석)

  • Lee, Seokki;Kim, Poongzag
    • Analytical Science and Technology
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    • v.7 no.4
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    • pp.427-434
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    • 1994
  • For the analysis of the relatively volatile lead in blood by GFAAS(graphite furnace atomic absorption spectrophotometer), one can not raise the ashing temperature beyond certain degree due to the elevation of the baseline. Previous investigations showed that background is stabilized when the ashing temperature is raised to $700^{\circ}C$ using a matrix modifier. In this study, same result was obtained at the ashing temperature of around $550^{\circ}C$ even when the matrix modifier is not used and only Triton X-100 is used as a diluent, on an instrument which is equipped with both temperature and current controller(Shimadzu, AA-6501S) and thus the temperature control is fast and accurate. Background correction methods of $D_2$ arc and SR(self reversal) were reviewed. The results show that the absorbance is higher for the $D_2$ arc method, but the background correction is higher for the SR method.

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Matrix Modification for Electrothermal Atomic Absorption Spectrophotometric Determination of Trace Manganese in Seaweeds (해조류중 흔적량 망간의 전열원자흡수 분광광도법 정량을 위한 매트릭스 개선에 관한 연구)

  • 최종문;강동수
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.75-81
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    • 2000
  • A matrix modification was studied for the determination of trace manganese in several seaweeds by electrothermal atomic absorption spectrophotometry(ETAAS). The type and quantity of modifiers were investigated to realize the efficient modification. Palladium was chosen as a single modifier. By the addition of palladium(5$\mu\textrm{g}$/$m\ell$) to 2ng/$m\ell$ manganese solution, the temperatures were raised from 1,00$0^{\circ}C$ to 1,20$0^{\circ}C$ for the charring and from 2,10$0^{\circ}C$ to 2,20$0^{\circ}C$ for the atomization as well as the sensitivity and reproducibility were improved. With such optimum conditions, the trace amount of manganese in several seaweeds(laver, tangle and brown seaweed) could be determined by a calibration curve method, and good recoveries of more than 965 were also obtained in the samples in which a given amount of manganese was spiked. The detection limit of this method was about 0.048ng/$m\ell$.

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Electrical and Thermo-mechanical Properties of DGEBA Cycloaliphatic Diamine Nano PA and SiO2 Composites

  • Trnka, Pavel;Mentlik, Vaclav;Harvanek, Lukas;Hornak, Jaroslav;Matejka, Libor
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2425-2433
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    • 2018
  • This study investigates a new organic based material and its dielectric and mechanical properties. It is a comprehensive nanocomposite comprising a combination of various types of nanofillers with hydrophobic silica nanoparticles (AEROSIL R 974) as a matrix modifier and a polyamide nano nonwoven textile, Ultramid-Polyamide 6, pulped in the electrostatic field as a dielectric barrier. The polymer matrix is an epoxy network based on diglycidyl ether of bisphenol A (DGEBA) and cycloaliphatic diamine (Laromine C260). The designed nanocomposite material is an alternative to the conventional three-component composites containing fiberglass and mica with properties that exceed current electroinsulating systems (volume resistivity on the order of $10^{16}{\Omega}{\cdot}m$, dissipation factor tan ${\delta}=4.7{\cdot}10^{-3}$, dielectric strength 39 kV/mm).

A Study on the Relationship between Residual Stress and Wear Peroperty in Hypereutectic Al-Si Alloys (과공정 Al-Si 합금의 마모 특성에 미치는 잔류응력의 영향에 관한 연구)

  • Kim, Heon-Joo;Kim, Chang-Gyu
    • Journal of Korea Foundry Society
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    • v.20 no.2
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    • pp.89-96
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    • 2000
  • The effects of modification processing on the refinement of primary Si and the wear behavior of hyper-eutectic Al-Si alloys have been mainly investigated. Refining effects of primary Si in Al-17%Si alloy was more efficient than that of B.390 alloy. Optimum condition of getting the finest primary Si microstructure was when AlCuP modifier is added into the melt at $750^{\circ}C$ and held it at $700^{\circ}C$ for 30 minutes. Wear loss in the specimens of as-cast condition decreases as the size of primary Si decreases, in the order of B.390 alloy, B.390 alloy with AlCuP addition, Al-17%Si alloy and Al-17%Si alloy with AlCuP addition. Wear loss in the aged condition of Al-17%Si alloy, B.390 alloy and B.390 alloy with AlCuP addition decreased due to the increase of compressive residual stress in the matrix by the aging treatment. While, wear loss increased in the aged specimens of Al-17%Si alloy with AlCuP addition and Hepworth addition in which compressive residual stress decreases by the aging treatment. Therefore, it is assumed that higher compressive residual stress in the matrix can reduce the wear loss in composite materials such as hyper-eutectic Al-Si alloys.

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Preparation and Performance Improvement of Polylactic acid based composites by stereocomplex (스테레오 컴플렉스를 이용한 폴리유산 복합재 제조 및 성능 개선)

  • Hong, Chae-Hwan;Kim, Yeon-Hee;Park, Jun-Seo;Nam, Byeong-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1671-1676
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    • 2015
  • A unique crystallization behavior of poly(L-lactide)(PLLA)/poly(D-lactide)(PDLA) stereocomplex(SC) was observed when a PLLA/PDLA blend was subjected to the specific melting conditions. Therefore, we tried to blend PLLA and PDLA at overall composition to form PLA stereocomplexes. Moreover, impact modifier and reinforcement materials such as talc and glass fiber added to enhance the mechanical and thermal properties such as impact strength and heat distortion temperature(HDT). As a result, we got one representative result, one composite recipe with HDT $115^{\circ}C$. For more economic technology, we tried to blend PLLA and Polypropylene at overall composition and we got another representative result which could be applied to current PP/talc composites and ABS materials. The core technology of this might be the well dispersion of glass fibers into the matrix resin such as PP, PLLA and impact strength modifier.