L-lactide macromonomer synthesis initiated by new cyclic tin alkoxides functionalized for brushlike structures
2001 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, no 21, 7281-7287 p.Article in journal (Refereed) Published
L-Lactide macromonomers with an incorporated double bond were successfully synthesized by controlled ring-opening polymerization initiated by two new cyclic tin alkoxides (1,1-di-n-butyl-stanna-2,7-dioxacyclo-4-heptene and 9,9,20,20-tetrabutyl-8,10,19,21-tetraoxa-9,20-distanna-dispiro[22.214.171.124]d ocosa-2,14-diene). Initiators and crude reaction mixtures were characterized by NMR. H-1 NMR analysis showed that the initiators were completely reacted in the polymerization and that both tin-oxygen bonds were reactive and participated in propagation. The polymerizations were performed in chloroform at 60 degreesC, and the molecular weight was effectively controlled by adjusting the monomer-to-initiator ratio. The molecular weight distribution was narrow (<1.1) for both high and low molecular weights (3000-72 000 g/mol). A plot of M-n vs conversion was linear up to a conversion of 98%, showing a system propagating in a controlled manner. The kinetic investigation showed that all of the polymerizations were first order in monomer and that no termination reactions occurred during polymerization.
Place, publisher, year, edition, pages
2001. Vol. 34, no 21, 7281-7287 p.
ring-opening polymerization, poly(l-lactide) macromonomers, macrocyclic polymerization, multiblock copolymers, aluminum alkoxides, graft-copolymers, polylactones, polyesters, pentaerythritol, caprolactone
IdentifiersURN: urn:nbn:se:kth:diva-13186DOI: 10.1021/ma0106898ISI: 000171386300011OAI: oai:DiVA.org:kth-13186DiVA: diva2:321693
QC 201006022010-06-022010-06-022012-06-12Bibliographically approved