• 제목/요약/키워드: Reactive extrusion

검색결과 36건 처리시간 0.022초

Reactive Extrusion of Starch-g-Polyacrylonitrile in the Preparation of Absorbent Materials

  • Yoon, Kee-Jong;Carr, M.E.;Bagley, E.B.
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1990년도 제2차 학술발표초록집
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    • pp.8-8
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    • 1990
  • A new method for the graft polymerization of acrylonitrile onto starch is presented. Graft polymerization of acrylonitrile onto starch and the subsequent hydrolysis in sodium hydroxide solution to prepare absorbents is well known. This process has been utilized to produce the commercial product, Super Slurper. In a typical batch process, ~5% starch in water mixture is gelatinized at $95^{\circ}C$ under stirring for 1 hour then cooled to room temperature. The graft polymerization itself is carried out for approximately 2 hours at $25~30^{\circ}C$ on the gelatinized starch by eerie ion initiation. In this study, graft polymerization of acrylonitrile onto starch via a reactive extrusion process which is a continuous, efficient process is described. Initial concentration of starch in water is 35% and the reaction temperatures are between $50~80^{\circ}C$. However, the most significant difference in the reactive extrusion process is the short time in which the graft polymerization takes place. Preliminary results on the properties of graft polymerization products obtained from the reactive extrusion process are compared to those obtained from the batch process as well as the absorbency of the hydrolyzed samples. Absorbent material has also been prepared by sequential grafting and saponification in the extruder followed by a 2 hour heat treatment of the extrudate in an air circulated oven at $100^{\circ}C$.

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Preparation of Nylon 6/ Clay Nanocomposites by Reactive Extrusion

  • Soonho Lim;Park, Jung-Hoon;Kim, Woo-Nyeon;Lee, Sang-Soo;Kim, Junkyung
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 추계학술발표대회 논문집
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    • pp.16-20
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    • 2003
  • As the preliminary works for the preparation of exfoliated nanocomposites by reactive extrusion (REX) the modified anionic polymerization proceeded in a flask using an $\varepsilon$-caprolactam, catalyst, initiator, and clay. Polymerization methods were classified with a variation of the clay adding time. Intercalations mechanism of clay layers was investigated by measuring the WAXD peaks of clay with polymerization. In the preparation of nanocomposites, the molecular weight of nylon 6 was affected by the clay content. From the mechanical property measurement, improved properties were obtained in comparison to the neat nylon 6, and these properties were also affected by the molecular weight.

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Lauryl lactam-EPDM의 연속중합 및 In-Situ 블렌드 (Continuous Polymerization and In-Situ Blends of Lauryl lactam-EPDM)

  • 계형산
    • Elastomers and Composites
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    • 제33권4호
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    • pp.255-266
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    • 1998
  • 본 연구는 한대의 modular 치합형 동방향회전 이축 압출기에서 음이온 중합 mechanism을 이용하여 Lauryl lactam 단량체의 고분자합성 도중 EPDM을 투입하여 연속적 중합을 수행한 연구이다. PA 12의 반응 도중 EPDM과 반응블렌드(reactive blend)를 하고 기계적블렌드와 그 물성을 비교 측정하였다.

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Effects of High-Intensity Ultrasound & Supercritical Nitrogen on PP-MA Reactive Extrusion

  • Sohn, Chang-Hee;Shim, Dong-Chul;Lee, Jae-Wook
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.369-369
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    • 2006
  • Compatibilizers contribute to many processes in polymer industry, such as manufacturing polymer blends and composites. They are usually designed to be block or graft form which is combined in polar and non-polar parts in the first synthesis process level, for example, the general form of maleic anhydride (MA) as a compatiblizer is a grafted counterpart. However, the process of making the compatibilizer is related to the first synthesis level and it has some problems, such as high cost, poor processability, limitation on use and properties, and so on. So, in order to improve its poor processability and overcome the limitation on use, we developed compatibilizers which have various chemical forms by high intensity ultrasound and super critical fluid nitrogen in polymer melt reactive extrusion.

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반응압출법에 의해 화학적으로 개질된 PLA의 열적 특성, 유연학적 성질 및 생분해도 (Thermal and Rheological Properties, and Biodegradability of Chemically Modified PLA by Reactive Extrusion)

  • 장우열;홍기헌;조백희;장상희;이상일;김봉식;신부영
    • 폴리머
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    • 제32권2호
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    • pp.116-124
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    • 2008
  • 본 연구는 식물유래 생분해성 고분자인 poly(lactic acid)(PLA)의 가공성을 향상시키기 위하여 기능성 단량체인 glycidyl methacrylate(GMA)와 반응 개시제를 첨가하여 반응압출법으로 PLA를 개질한 후 겔화도, 열적성질, 유변학적 특성 및 생분해도를 조사하였다. 개질 PLA및 순수 PLA의 열적특성은 시차열량분석기(DSC)를 이용하여 측정하였고 유변학적 특성은 복합점도(${\eta}^*$), 저장 탄성률(G'), log G' vs. log G" 선도를 이용하여 분석 비교하였다. GMA가 포함되지 않고 개시제로만 개질된 PLA의 복합점도 및 저장탄성률도 순수 PLA보다 증가하였지만, 여기에 GMA를 첨가하여 개질하면 더욱 향상된 복합점도와 저장탄성률을 갖는 개질 PLA를 얻을 수 있었다. 개시제의 함량에 따라 최고 높은 복합점도 및 저장탄성률 증가 효과를 보이는 최적의 GMA함량이 존재하였다. 그리고 GMA가 함유된 개질 PLA의 생분해도는 약간 낮아지는 경향을 보였다.

INLINE NEAR INFRARED (NIR) SPECTROSCOPY FOR PROCESS CONTROL IN POLYMER EXTRUSION

  • Rohe, Thomas;Koelle, Sabine;Becker, Wolfgang;Eisenreich, Norbert;Eyerer, Peter
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1082-1082
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    • 2001
  • Extrusion is one of the most important processes in polymer industry. The characterization of the polymer melt during processing will improve this process noticeably, One possibility of characterizing the actual processed polymer melt is the inline near infrared (NIR) spectroscopy, With this method several polymer properties can be observed during processing, e.g. composition, moisture ormechanical properties of the melt. For this purpose probes for transmission and reflection measurements have been developed, withstanding the high temperatures and pressures appearing during extrusion process (tested up to 300$^{\circ}C$ and 10 ㎫). For the transmission system an optical bypass was developed to eliminate disturbing spectral influences and hence increase the long term stability, which is the prerequisite for an industrial application. Measurements in transmission and reflection produced comparable results (or blending processes, where the prediction error was less than 1%. An optimum RMSEP of only 0.24% was found for preprocessed polymer blends measured in transmission on a laboratory extruder. A transflection measurement allowed for the first time the recording of relevant NIR-spectra in the screw area of an extruder. The application to a (PE+PP) blending process delivered promising results. This new measurement mode allows the observation of the ongoing processes within the screw area, which is of maximum Interest for reactive extrusion processes. Due to economic reasons the calibration transfer between different extrusion systems is also of high importance. Investigations on simulated and real-world spectra showed that a calibration transfer is possible. A new method alternatively to the well-known direct standardization procedures was developed, which is based on an automatic data pretreatment. This procedure delivers comparable results for the calibration transfer. Overall this paper presents concepts, components and algorithms for the inline near infrared (NIR) spectroscopy for polymer extrusion, which allows the use of it in a real industrial extrusion process.

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