Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Modulated temperature differential scanning calorimetry for examination oftristearin polymorphism: I. Effect of operational parameters
Autore:
Singh, SK; Jalali, AF; Alden, M;
Indirizzi:
Pharmacia & Upjohn IAB, Dept Pharmaceut Technol, S-75182 Uppsala, Sweden Pharmacia & Upjohn IAB Uppsala Sweden S-75182 l, S-75182 Uppsala, Sweden Univ Uppsala, Ctr Biomed, Dept Pharmaceut Chem Phys & Inorgan Chem, S-75123 Univ Uppsala Uppsala Sweden S-75123 ut Chem Phys & Inorgan Chem, S-75123
Titolo Testata:
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
fascicolo: 4, volume: 76, anno: 1999,
pagine: 499 - 505
SICI:
0003-021X(199904)76:4<499:MTDSCF>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
SATURATED MONOACID TRIGLYCERIDES; SYNCHROTRON RADIATION; PHASE-TRANSITIONS; FOOD EMULSIFIERS; THERMAL-ANALYSIS; TRIPALMITIN; DSC; CRYSTALLIZATION; BEHAVIOR;
Keywords:
differential scanning calorimetry; metastable forms; MTDSC; modulated temperature; oscillating; phase behavior; polymorphism; triglycerides; tristearin;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
32
Recensione:
Indirizzi per estratti:
Indirizzo: Singh, SK Pharmacia & Upjohn Inc, 7000 Portage Rd, Kalamazoo, MI 49001 USAPharmacia & Upjohn Inc 7000 Portage Rd Kalamazoo MI USA 49001 SA
Citazione:
S.K. Singh et al., "Modulated temperature differential scanning calorimetry for examination oftristearin polymorphism: I. Effect of operational parameters", J AM OIL CH, 76(4), 1999, pp. 499-505

Abstract

The transformations of tristearin were examined by modulated temperature differential scanning calorimetry (MTDSC) in order to study the effect of operational parameters on the nature of information obtained from this technique. Tristearin has been used as a model polymorphic system showing metastable phases and complicated transformation routes occurring at relatively slow rates. The parameters examined were underlying heating/cooling rates andthe amplitude of modulation. The first conclusion is that MTDSC enables overlapping alpha-melting and beta-crystallization events to be separated, thus increasing the information obtained compared to normal thermal analysis. Other general conclusions are that observation of reversible processes is strongly influenced by the underlying heating rate; low to moderate heatingrates are recommended. Amplitude of modulation has a complicated effect onthe phenomenon being studied; when studying systems that exhibit metastable or polymorphic transitions, it is recommended that a range of amplitudes be tested to enable confirmation of whether an observed "recrystallization"effect is a new phase or the same phase as the one melting. Cooling with modulation disturbs the crystallization process, possibly leading to smalleror imperfect crystals; however, the phases obtained are not different compared to normal DSC. The usefulness of MTDSC in analyzing these types of complicated systems is primarily qualitative at the moment. Some recommendations have been made as to the combinations of parameters for studying such systems.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/07/20 alle ore 22:54:03