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Titolo:
Effect of the agitation rate on the generation of low-crystallinity cellulose from phosphoric acid
Autore:
Kumar, V; Kothari, S; Banker, GS;
Indirizzi:
Univ Iowa, Coll Pharm, Div Pharmaceut, Iowa City, IA 52242 USA Univ Iowa Iowa City IA USA 52242 Div Pharmaceut, Iowa City, IA 52242 USA
Titolo Testata:
JOURNAL OF APPLIED POLYMER SCIENCE
fascicolo: 11, volume: 82, anno: 2001,
pagine: 2624 - 2628
SICI:
0021-8995(200112)82:11<2624:EOTARO>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Keywords:
low-crystallinity cellulose; cellulose polymorphs; direct-compression cellulose excipient; microcrystalline cellulose; hydrocellulose; tabletting excipient;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
10
Recensione:
Indirizzi per estratti:
Indirizzo: Kumar, V Univ Iowa, Coll Pharm, Div Pharmaceut, Iowa City, IA 52242 USA Univ Iowa Iowa City IA USA 52242 maceut, Iowa City, IA 52242 USA
Citazione:
V. Kumar et al., "Effect of the agitation rate on the generation of low-crystallinity cellulose from phosphoric acid", J APPL POLY, 82(11), 2001, pp. 2624-2628

Abstract

Changes in the basic powder properties of low-crystallinity powder cellulose (LCPC) as a function of the agitation rate used during its generation from phosphoric acid were investigated. We reacted cotton linter with phosphoric acid (85% w/v) at room temperature for an hour and then at 50 degreesC for 3 h to produce the LCPC solution. The latter was slowly added to water (ca. 10 times the volume of phosphoric acid used) at a constant agitation rate of 700, 2000, or 4000 rpm. LCPC powder thus formed was collected by filtration, washed with water and acetone, and dried at 30 degreesC. Scanning electron micrographs showed the three products to be highly aggregated in structure. The crystallinities of LCPC prepared at 700, 2000, and 4000 rpm were 39, 31, and 24%, respectively. The crystalline component of LCPC produced at 700 and 2000 rpm contained both cellulose II (major component) and cellulose I (minor component), whereas LCPC generated at 4000 rpm belonged tothe cellulose II crystal lattice. The porosity and true, bulk, and tap densities of LCPC made at 4000 rpm were 88.55% and 1.435, 0.138, and 0.164 g/cc, respectively. The corresponding values for LCPC made at 700 and 2000 rpmwere 60.30% and 1.452, 0.541, and 0.576 g/cc and 54.49% and 1.465, 0.583, and 0.667 g/cc, respectively. Avicel (R) PH-101, in contrast, had a degree of crystallinity of 89% and a true density value of 1.577 g/cc. The porosity, bulk density, and tap density values were intermediate to those of LCPC made at 4000 rpm and 700 or 2000 rpm. (C) 2001 John Wiley & Sons, Inc.

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Documento generato il 02/04/20 alle ore 08:38:53