New Sn(IV) and Ti(IV) bis(trimethylsilyl)amides in d,l-lactide polymerization, SEM characterization of polymers |
| |
| Authors: | Andrei Grafov Sirpa Vuorinen Marianna Kemell Markku Leskelä |
| |
| Institution: | a Department of Inorganic Chemistry, University of Helsinki, A.I. Virtasen aukio 1, PL 55, 00014 Helsinki, Finland
b V.I. Vernadskii Institute of General and Inorganic Chemistry, National Academy of Sciences, Prospekt Palladina 32/34, Kiev-142, UA-03142, Ukraine |
| |
| Abstract: | Ring-opening polymerization of d,l-lactide initiated with new chlorotris(bis(trimethylsilyl) amido) tin(IV), tetrakis(bis(trimethylsilyl)amido) tin(IV) and titanium(IV) was investigated. New complexes reveal practically quantitative conversion degrees and produced polymers with higher molecular weight with respect to reference alkoxo-species.The X-ray crystal structure of chlorotris(bis(trimethylsilyl)amido) tin (IV) was investigated. Axial enantiomerism of SnCl{N(SiMe3)2}3] molecules in solution was studied by high-field dynamic NMR, the value of Gibbs activation energy ΔG‡ = 59.5 kJ/mol.Field emission SEM investigation of bulk polymer samples and thin films on conductive Al foil revealed a stratified fibrous textures in the bulk polymers, as well as nanoscaled topographical features due to coils and entanglements of individual macromolecules in thin films. |
| |
| Keywords: | Tin bis(trimethylsilyl)amides Ring-opening polymerization d" target="_blank">d l-lactide" target="_blank">l-lactide Axial enantiomerism SEM |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
