Reference : Bulk polymerization of lactides initiated by aluminum isopropoxide. 1. Mechanism and ...
Scientific journals : Article
Engineering, computing & technology : Materials science & engineering
Physical, chemical, mathematical & earth Sciences : Chemistry
http://hdl.handle.net/2268/4394
Bulk polymerization of lactides initiated by aluminum isopropoxide. 1. Mechanism and kinetics
English
Degée, Philippe [University of Liège (ULg) > Department of Chemistry > Center for Education and Research on Macromolecules (CERM) > >]
Dubois, Philippe [University of LIège (ULg) > Department of Chemistry > Center for Education and Research on Macromolecules (CERM) > >]
Jérôme, Robert mailto [University of Liège (ULg) > Department of Chemistry > Center for Education and Research on Macromolecules (CERM) > >]
Sep-1997
Macromolecular Symposia
Wiley-V C H Verlag Gmbh
123
67-84
Yes (verified by ORBi)
International
1022-1360
1521-3900
Weinheim
[en] ring-opening polymerization (ROP) ; lactone
[en] Commercially available Al isopiopoxide (Al(OiPr)3) has proved to be an efficient initiator for the bulk polymerization of lactide. The ring-opening polymerization proceeds through a "coordination-insertion" mechanism and the selective rupture of the acyl-oxygen bond of the monomer Polyester chains are selectively end-capped with an aluminum alkoxide and an isopropoxy group. Therefore, substitution of Al tris(4-penten-1-olate) for Al(OiPr)3 leads to the formation of macromonomers In the temperature range from 110 to 150°C, polymerization is "living", i.e. the molecular weight can be predicted by the initial monomer-to-Al molar ratio and the monomer conversion. The narrower polydispetsity of poly(L,L-lactide) compared to the amorphous poly(D,L-lactide) ( 1.3 compared to 1.9, respectively), both prepared in the bulk, is thought to result from the restricted mobility of the crystallized isotactic polyester chains. When the temperature is increased up to 180°C, inter- and intramolecular transesterification reactions interfere with chain propagation.
Center for Education and Research on Macromolecules (CERM)
Politique Scientifique Fédérale (Belgique) = Belgian Federal Science Policy ; IRSIA ; Advanced Technics Company (Brussels)
Researchers
http://hdl.handle.net/2268/4394

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