Τίτλος:
Synthesis and characterization of chiral poly(alkyl isocyanates) by coordination polymerization using a chiral half-titanocene complex
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
A new chiral half-titanocene complex, [CpTiCl2(O-(S)-2-Bu)], is synthesized and characterized by 1H and 13C NMR spectroscopy. This complex is employed for the coordination polymerization of n-butyl and n-hexyl- isocyanate leading to chiral polymers, as revealed by their CD spectra. Only the left-handed helix is produced, due to the chiral (S)-2-butoxy group, which is bound to the polymer chain end. The polymerization of 3-(triethoxysilyl)propyl isocyanate produces less soluble polymers. On the other hand, phenyl isocyanate reacts slowly with the complex leading quantitatively and selectively to triphenyl isocyanurate. 2-Ethylhexyl isocyanate is slowly and selectively cyclotrimerized in the presence of the half-titanocene complex. However, a statistical copolymer of 2-ethylhexyl isocyanate and hexyl isocyanate is produced. The reaction of benzyl isocyanate with the complex leads to a mixture of low molecular weight polymer and cyclotrimer. The polymers are characterized using SEC, NMR, and CD spectroscopy and their thermal properties are investigated by TGA/DSC analysis. © 2015 Wiley Periodicals, Inc.
Συγγραφείς:
Choinopoulos, I.
Koinis, S.
Pitsikalis, M.
Περιοδικό:
Journal of Polymer Science Part A: Polymer Chemistry
Εκδότης:
John Wiley and Sons Inc
Λέξεις-κλειδιά:
Circular dichroism spectroscopy; Dichroism; Differential scanning calorimetry; Nuclear magnetic resonance spectroscopy; Organic polymers; Polymerization; Polymers; Synthesis (chemical); Thermogravimetric analysis, Chiral; Coordination polymerization; Isocyanates; Low-molecular-weight polymers; Statistical copolymers; Synthesis and characterizations; Titanocene complexes; Titanocenes, Coordination reactions
