Macromolecular engineering of polylactones and polylactides. 7. Structural analysis of copolyesters of epsilon-caprolactone and L- of D,L-lactide initated by Al(OiPr)3
[en] Copolymerization of mixtures of epsilon-caprolactone (epsilon-CL) and D,L- or L-lactide has been initiated by aluminum isopropoxide. On the basis of the monomer reactivity ratios and assuming that no side reaction occurs, tapered copolymers should be formed particularly when D,L-lactide is the comonomer rather than L-lactide. The sequential distribution of the comonomers has been analyzed by an original method based on the quantitative measurement of the carbonyl C-13 signals. Comparison of the experimental and the theoretical distributions clearly shows that transesterification reactions occur during copolymerization through both intra- and intermolecular mechanisms. Gel permeation chromatography and differential scanning calorimetry data support that conclusion. The D,L-lactide-based copolymers have however a more blocky structure than those containing L-lactide, and they are also less sensitive to transesterification reactions.
Research Center/Unit :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Chemistry Materials science & engineering
Author, co-author :
Vanhoorne, Pierre; Université de Liège - ULiège > Department of Chemistry > Laboratory of Macromolecular Chemistry and Organic Catalysis
Dubois, Philippe; Université de Liège - ULiège > Department of Chemistry > Laboratory of Macromolecular Chemistry and Organic Catalysis
Jérôme, Robert ; Université de Liège - ULiège > Department of Chemistry > Laboratory of Macromolecular Chemistry and Organic Catalysis
Teyssié, Philippe ; Université de Liège - ULiège > Department of Chemistry > Laboratory of Macromolecular Chemistry and Organic Catalysis
Language :
English
Title :
Macromolecular engineering of polylactones and polylactides. 7. Structural analysis of copolyesters of epsilon-caprolactone and L- of D,L-lactide initated by Al(OiPr)3
Publication date :
06 January 1992
Journal title :
Macromolecules
ISSN :
0024-9297
eISSN :
1520-5835
Publisher :
American Chemical Society, Washington, United States - District of Columbia
F.R.S.-FNRS - Fonds de la Recherche Scientifique BELSPO - Politique scientifique fédérale IRSIA - Institut pour l'Encouragement de la Recherche Scientifique dans l'Industrie et l'Agriculture
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