SINTHESIS AND PHYSICOCHEMICAL CHARACTERIZATION OF WELL-DEFINED POLY(BUTADIENE 1,3)-block-(DIMETHYLSILOXANE) COPOLYMERS

CIOLINO A; GOMEZ LR; VEGA DA; VILLAR MA; VALLES EM

Buenos Aires

Congreso; XXII Interamerican Congress of Chemical Engineering; 2005

AAIQ

Model diblock copolymers of polybutadiene-1,3 and poly(dimethylsiloxane) (PB-b-PDMS) were synthesized by the sequential anionic polymerization (high vacuum techniques) of butadiene 1,3 and hexamethylciclotrisiloxane (D3). The block copolymers so obtained were physico-chemically characterized by nuclear magnetic resonance (1H− and 13C−NMR), size-exclusion chromatography (SEC), Fourier Transform infrared spectroscopy (FTIR), and rheology. SEC combined with 1H-NMR analysis indicate that the PB-b-PDMS copolymers exhibit molar masses between 8,000 and 12,000 g/mol, narrow polydispersity index (Mw/Mn), and chemical compositions which vary from low to medium siloxane content. According to the rheological experiments, the model block copolymers present morphological arrangements that vary from spherical and cylindrical to gyroid and lamellar domains. b-PDMS) were synthesized by the sequential anionic polymerization (high vacuum techniques) of butadiene 1,3 and hexamethylciclotrisiloxane (D3). The block copolymers so obtained were physico-chemically characterized by nuclear magnetic resonance (1H− and 13C−NMR), size-exclusion chromatography (SEC), Fourier Transform infrared spectroscopy (FTIR), and rheology. SEC combined with 1H-NMR analysis indicate that the PB-b-PDMS copolymers exhibit molar masses between 8,000 and 12,000 g/mol, narrow polydispersity index (Mw/Mn), and chemical compositions which vary from low to medium siloxane content. According to the rheological experiments, the model block copolymers present morphological arrangements that vary from spherical and cylindrical to gyroid and lamellar domains.