title: Synthesis of trimethoxy- or triethoxysilane-endcapped polylactones via a bismuth(III)hexanoate-catalyzed one-pot-procedure.
abstract: It was shown that bismuth(III)hexanoate (Bi(OHex)3) efficiently and selectively catalyzes the addition of tetra(ethylene glycol) (TEG) onto the isocyanate group of 3-isocyanatopropyl triethoxysilane, IPTES. delta-Valerolactone (deltaVL), epsilon-caprolactone (epsilonCL) and D,L-lactide were polymerized by initiation with TEG/Bi(OHex)3. The resulting telechelic polyesters were in situ functionalized with IPTES or with 3-isocyanatopropyl trimethoxysilane, IPTMS. Using pentaerythritol as co-initiator of Bi(OHex)3 and epsilonCL as monomer, star-shaped polylactones having triethylsilyl end-groups were synthesized in a one-pot-procedure. All functionalized polyesters were characterized by 1H-NMR and 13C-NMR spectroscopy and by MALDI-TOF mass spectrometry. Bi(OHex)3 is a remarkable initiator and catalyst, because of its extraordinary low toxicity.
authors.affiliation: Institut für Technische und Makromolekulare Chemie, Bundesstr 45, D-20146 Hamburg, Germany. kricheld@chemie.uni-hamburg.de
authors.forename: Hans R
authors.initials: HR
authors.lastname: Kricheldorf
authors.forename: Heiko
authors.initials: H
authors.lastname: Hachmann-Thiessen
authors.forename: Gert
authors.initials: G
authors.lastname: Schwarz
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002208:Caproates / Q000737:chemistry; D002384:Catalysis; D017953:Isocyanates / Q000138:chemical synthesis*; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D008954:Models, Biological; D011091:Polyesters / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis*; D012821:Silanes / Q000138:chemical synthesis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: C492426:(3-isocyanatopropyl) triethoxysilane; C514436:3-isocyanatopropyl trimethoxysilane; D002208:Caproates; D017953:Isocyanates; D007783:Lactones; D011091:Polyesters; D011108:Polymers; D012821:Silanes; C037652:hexanoic acid; D011092:Polyethylene Glycols; C033616:poly(lactide); C121056:caprolactone; C062968:lactide-caprolactone copolymer; D001729:Bismuth; C071717:trimethoxysilane