Linked Life Data

16004449

Source:http://linkedlifedata.com/resource/pubmed/id/16004449

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-7-11
pubmed:abstractText
(-)-Menthide, a seven-membered lactone derived from the natural product (-)-menthol, was polymerized using a structurally defined zinc-alkoxide catalyst to form an aliphatic polyester. The polymer was fully characterized by NMR spectroscopy, size exclusion chromatography, and matrix-assisted laser desorption ionization mass spectrometry. The polymerization reaction occurred in a controlled fashion and polymer samples with M(n) values up to 90 kg mol(-1) were obtained by varying the catalyst loading. Monitoring of the rate of polymerization by in situ FT-IR spectroscopy (ReactIR) revealed a first order dependence on (-)-menthide. The temperature dependence of the observed rate constant between 30 and 90 degrees C was well described by the Arrhenius equation and gave E(a) = 38.4 +/- 0.9 kJ mol(-1). Thermodynamic parameters (deltaH(p) degrees = -16.8 +/- 1.6 kJ mol(-1), deltaS(p) degrees = -27.4 +/- 4.6 J mol(-1) K(-1)) for the polymerization of (-)-menthide were also determined by measuring the equilibrium monomer concentration at different temperatures ranging from 40 to 100 degrees C. The equilibrium monomer concentrations at 25 and 100 degrees C were calculated to be 0.031 +/- 0.018 and 0.120 +/- 0.063 M, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1525-7797
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2091-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Catalytic polymerization of a cyclic ester derived from a "cool" natural precursor.
pubmed:affiliation
Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't