Controlled ring-opening polymerization of L-lactide and 1,5-dioxepan-2-one forming a triblock copolymer
2000 (English)In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 38, no 10, 1774-1784 p.Article in journal (Refereed) Published
Novel elastomeric A-B-A triblock copolymers were successfully synthesized in a new two-step process: controlled ring-opening polymerization of the cyclic etherester 1.5-dioxepan-2-one as the amorphous middle block (B-block) followed by addition and polymerization of the two semicrystalline L-lactide blocks (A-block). A 1,1,6,6-tetra-n-butyl-1,6-distanna-2,5,7,10-tetraoxacyclodecane initiator system was utilized and the reaction was performed in chloroform at 60 degrees C. A good control of the synthesis was obtained, resulting in well defined triblock copolymers. The molecular weight and chemical composition were easily adjusted by the monomer-to-initiator ratio. The triblock copolymers formed exhibited semicrystallinity up to a content of 1,5-dioxepan-2-one as high as 89% as determined by differential scanning calorimetry. WAXS investigation of the triblock copolymers showed a crystal structure similar to that of the pure poly(L-lactide).
Place, publisher, year, edition, pages
2000. Vol. 38, no 10, 1774-1784 p.
ring-opening polymerization, triblock copolymer, solution polymerization, thermal properties, differential scanning calorimetry, block-copolymers, polylactides, homopolymers, lactones
IdentifiersURN: urn:nbn:se:kth:diva-19706ISI: 000086628900061OAI: oai:DiVA.org:kth-19706DiVA: diva2:338398
QC 201005252010-08-102010-08-10Bibliographically approved