Synthesis of Powdered Polymeric Microparticles by Using Supercritical Carbon Dioxide as the Polymerizing Medium

Kamrupi, I. R.; Dolui, Swapan Kumar

doi:10.1080/10426914.2010.491008

Cited by 7 publications

(6 citation statements)

References 15 publications

(13 reference statements)

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“…At the end, the reactor was allowed to cool down to room temperature. The pressure was then slowly released and at atmospheric pressure the polymeric product was recovered from the reactor as a fine white powder followed by washing and vacuum drying 22…”

Section: Methodsmentioning

confidence: 99%

Polymer‐supported heterogeneous titanium‐based Ziegler‐Natta catalyst for ethylene polymerization

Kalita

Kamrupi

Pokhrel

et al. 2012

J of Applied Polymer Sci

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Reported here in, is the synthesis of polystyrene (PS)-supported Ziegler-Natta catalyst (PS-TiCl 4 ) by the reaction of PS and titanium tetrachloride (TiCl 4 ). PS was synthesized by emulsion polymerization using super critical CO 2 (sc-CO 2 ) as a medium. Three catalysts were synthesized by varying the TiCl 4 /PS weight ratio in hexane medium. The resulting catalysts were characterized by Fourier transformed-infrared spectroscopy, UV-visible spectroscopy, scanning electron microscope and energy dispersive X-ray detector, X-ray diffraction analysis. The acidity of the catalysts in an acetone/water solution was measured by pH meter. The thermogravimetric analysis reveals that catalysts are stable upto 150-180 C. Due to their higher degree of thermal stability these catalysts may potentially be used as a support in conventional Ziegler-Natta catalyst for ethylene polymerization. These catalysts also showed good storability and its overall catalytic productivity are found to be 3720 g PE/g Ti. The productivity of the catalysts also depended on the titanium concentration in the polymer matrix.

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Section: Methodsmentioning

confidence: 99%

Polymer‐supported heterogeneous titanium‐based Ziegler‐Natta catalyst for ethylene polymerization

Kalita

Kamrupi

Pokhrel

et al. 2012

J of Applied Polymer Sci

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“…Hitherto, various materials, including polymers, polyelectrolyte multilayers, silicas, and so on, have been investigated as potential carriers for this purpose [2][3][4][5][6][7]. Among them, silicas have drawn much attention because of their attractive features of availability, nontoxicity, stability, well-defined surface property, tunable pore size, and pore connectivity.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Macroporous Silica Spheres for Drug Delivery

Huang

Long

et al. 2013

Materials and Manufacturing Processes

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In pharmaceutical science, construction of drug delivery system based on various carriers is a great challenge. Here we proposed a new silica carrier for drug delivery. The carrier is characterized by penetrable macropores and large pore volume, which renders it an ideal carrier for drug loading especially for macromolecular drugs. Bovine serum albumin (BSA) and oxaprozin were used as models to investigate its delivery behavior. From the results, it demonstrates that the drug loading capacity is very high (for BSA, it reaches 212.2 wt% [drug/ carrier]). It is also found that an ultra-fast release for oxaprozin was achieved on this carrier, indicating the material is suitable for constructing enhanced delivery platform for specific drugs to improve the bioavailability.

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“…Many stabilisers/surfactants like polydimethylsiloxane (PDMS), PFPE, sodium bis(3,5,5-trimethyl-1-hexyl)sulphosuccinate (AOT-TMH), (trifluoromethyl)undecafluorocyclo-hexane (C 7 F 14 ), etc. are found to be suitable for the formation of stable microemulsion of water in CO 2 (w/c) [13,14]. Micellar droplets possess a dynamic exchange of their contents that facilitates the reaction between reactants dissolved in different droplets.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of stable dispersion of copper nanoparticles in a water-in-supercritical carbon dioxide using polydimethylsiloxane as the stabiliser

Kamrupi

Dolui

2012

Journal of Experimental Nanoscience

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This study reportes the synthesis of stable dispersion copper nanoparticles by chemical reduction of copper chloride (CuCl 2) in a water-in-supercritical carbon dioxide medium using sodium borohydrate (NaBH 4) as a reducing agent, polydimethylsiloxane as the stabiliser and sodium bis(2-ethylhexyl)sulphosuccinate (AOT) as co-surfactant at temperature 40 C and pressure in the range 2000-2400 psi. UV-visible spectroscopy exhibits a typical emission peak at 560-590 nm for Cu nanoparticles. By changing the reaction pressure and the stabiliser concentration, the size and the shape of the copper nanoparticles could be easily controlled. The X-ray diffraction pattern reveals that the Cu nanoparticles are formed in the range 4-8 nm, which is consistent with the transmission electron microscopy images.

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Synthesis of Powdered Polymeric Microparticles by Using Supercritical Carbon Dioxide as the Polymerizing Medium

Cited by 7 publications

References 15 publications

Polymer‐supported heterogeneous titanium‐based Ziegler‐Natta catalyst for ethylene polymerization

Polymer‐supported heterogeneous titanium‐based Ziegler‐Natta catalyst for ethylene polymerization

Synthesis of Macroporous Silica Spheres for Drug Delivery

Synthesis of stable dispersion of copper nanoparticles in a water-in-supercritical carbon dioxide using polydimethylsiloxane as the stabiliser

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