• Polymer Science and Technology
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• v.7 no.4
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• pp.397-404
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• 1996

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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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 $100^{\circ}C$.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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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.

• Polymer Science and Technology
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• v.7 no.3
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• pp.280-283
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• 1996

• Elastomers and Composites
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• v.33 no.4
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• pp.255-266
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• 1998

One-step continuous reactive blend with EPDM is investigated using a modular intermeshing corotating twin screw extruder This was performed via anionic polymerization mechanism. Mechanical properties were characterized and compared with mechanical blends.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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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.

• Polymer Science and Technology
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• v.9 no.3
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• pp.184-192
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• 1998

• Food Science and Industry
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• v.47 no.4
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• pp.55-62
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• 2014

• Polymer(Korea)
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• v.32 no.2
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• pp.116-124
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• 2008

A commercialized biobased and biodegradable poly(lactic acid)(PLA) containing the functional monomer of glycidyl methacrylate (GMA) was chemically modified using reactive extrusion to enhance its melt strength. Modified PLAs were prepared with various contents of GMA and initiator, and were characterized by observing their gel fraction, thermal properties, melt viscoelasticity and biodegradability. The complex viscosity and storage modulus of chemically modified PLA with the initiator alone was increased by addition of initiator and were more increased in the presence of GMA. There was a optimum content of GMA showing the maximum complex viscosity with the amount of initiator. The biodegradebility of modified PLA was slightly decreased by addition of GMA.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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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.