Abstract
The ring-opening polymerization of L-lactide (L-LA) initiated by 1-dodecanol/tin(II) octoate was carried out in supercritical chlorodifluoromethane at 110 °C under a pressure of 200 bar. MALDI-TOF mass spectroscopy and 1H NMR studies suggested that polymerization proceeded via a traditional coordination-insertion mechanism involving a tin alkoxide bond and the cleavage of the acyl-oxygen bond of the monomer. The polymerization was controlled using the linear relation between ln([LA] 0/[LA]) on the polymerization time and the molecular weight on conversion. The relative polymerization rate constants increased with increasing tin(II) octoate and 1-dodecanol concentrations. Gel permeation chromatography analysis indicated that the molecular weight distribution was bimodal, at least for certain monomer conversion. The bimodal distribution may be a result of specific intermolecular interactions between chlorodifluoromethane and hydroxyl groups on 1-dodecanol or on dormant macromolecules. The mechanisms of the initiation and chain transfer steps of L-lactide polymerization in supercritical chlorodifluoromethane are proposed.
| Original language | English |
|---|---|
| Pages (from-to) | 8923-8930 |
| Number of pages | 8 |
| Journal | Macromolecules |
| Volume | 36 |
| Issue number | 24 |
| DOIs | |
| Publication status | Published - 2003 Dec 2 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Materials Chemistry
Cite this
Kinetic and Mechanistic Studies of L-Lactide Polymerization in Supercritical Chlorodifluoromethane. / Pack, Ji Won; Kim, Soo Hyun; Park, Soo Young; Lee, Youn Woo; Kim, Young Ha.
In: Macromolecules, Vol. 36, No. 24, 02.12.2003, p. 8923-8930.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Kinetic and Mechanistic Studies of L-Lactide Polymerization in Supercritical Chlorodifluoromethane
AU - Pack, Ji Won
AU - Kim, Soo Hyun
AU - Park, Soo Young
AU - Lee, Youn Woo
AU - Kim, Young Ha
PY - 2003/12/2
Y1 - 2003/12/2
N2 - The ring-opening polymerization of L-lactide (L-LA) initiated by 1-dodecanol/tin(II) octoate was carried out in supercritical chlorodifluoromethane at 110 °C under a pressure of 200 bar. MALDI-TOF mass spectroscopy and 1H NMR studies suggested that polymerization proceeded via a traditional coordination-insertion mechanism involving a tin alkoxide bond and the cleavage of the acyl-oxygen bond of the monomer. The polymerization was controlled using the linear relation between ln([LA] 0/[LA]) on the polymerization time and the molecular weight on conversion. The relative polymerization rate constants increased with increasing tin(II) octoate and 1-dodecanol concentrations. Gel permeation chromatography analysis indicated that the molecular weight distribution was bimodal, at least for certain monomer conversion. The bimodal distribution may be a result of specific intermolecular interactions between chlorodifluoromethane and hydroxyl groups on 1-dodecanol or on dormant macromolecules. The mechanisms of the initiation and chain transfer steps of L-lactide polymerization in supercritical chlorodifluoromethane are proposed.
AB - The ring-opening polymerization of L-lactide (L-LA) initiated by 1-dodecanol/tin(II) octoate was carried out in supercritical chlorodifluoromethane at 110 °C under a pressure of 200 bar. MALDI-TOF mass spectroscopy and 1H NMR studies suggested that polymerization proceeded via a traditional coordination-insertion mechanism involving a tin alkoxide bond and the cleavage of the acyl-oxygen bond of the monomer. The polymerization was controlled using the linear relation between ln([LA] 0/[LA]) on the polymerization time and the molecular weight on conversion. The relative polymerization rate constants increased with increasing tin(II) octoate and 1-dodecanol concentrations. Gel permeation chromatography analysis indicated that the molecular weight distribution was bimodal, at least for certain monomer conversion. The bimodal distribution may be a result of specific intermolecular interactions between chlorodifluoromethane and hydroxyl groups on 1-dodecanol or on dormant macromolecules. The mechanisms of the initiation and chain transfer steps of L-lactide polymerization in supercritical chlorodifluoromethane are proposed.
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U2 - 10.1021/ma034910n
DO - 10.1021/ma034910n
M3 - Article
VL - 36
SP - 8923
EP - 8930
JO - Macromolecules
JF - Macromolecules
SN - 0024-9297
IS - 24
ER -