Lithium Naphtalenides in non-polar or in low polarity media: some insights regarding their use as iniciators in anionic polymerizations

NINAGO, MARIO DANIEL; SENA MARANI, MARÍA LORETA; GONZALEZ, VERÓNICA ALEJANDRA; SATTI, ANGEL JOSÉ; SARMORIA, CLAUDIA; VILLAR, MARCELO ARMANDO; VALLÉS, ENRIQUE MARCELO; CIOLINO, ANDRÉS EDUARDO

POLYMER BULLETIN

SPRINGER

Lugar: Berlin; Año: 2016 p. 1 - 17

0170-0839

The synthesis of bidirectional anionic initiators by the reaction betweenmetallic lithium (Li) and naphthalene (Naph), under mild conditions, in non-polar(benzene) or low-polarity media (benzene/THF mixtures) is reported. The efficiencyof these initiators to provide macromolecules with well-defined structures wasdemonstrated. Model linear homopolymers from styrene (S) or hexamethyl(ciclotrisiloxane)(D3) monomers were synthesized using classical anionic polymerization(high-vacuum techniques). The model polymers obtained were analyzedusing the conventional analytical techniques, and showed narrow molar mass distributions,a broad range of molar masses (from 3000 to 1,000,000 g/mol) andpolydispersity indexes (Mw/Mn) lower than 1.1. High molar mass polymers wereobtained using pure benzene as solvent, whereas lower molar masses were obtainedin benzene/THF mixtures in which the concentration of THF was lower than 10 %v/v. The ratio [Li]/[Naph] and the nature of the reaction medium are the experimentalparameters to be controlled to obtain the desired lithium naphthalenides.