“Nanostructurated Block Copolymers: Order-Order and Order-Disorder Transitions in Model Poly (butadiene-b-Dimethylsiloxanes”

LEOPOLDO R. GÓMEZ; DANIEL A. VEGA; MARIO D. NINAGO; ANDRÉS E. CIOLINO; ENRIQUE M. VALLÉS; MARCELO

Santiago de Chile (Chile)

Conferencia; The Tenth International Conference on Frontiers of Polymers and Advanced Materials (10th ICFPAM); 2009

In this work, we would like to present the morphological and rheological characterization of model butadiene-dimethylsiloxane block copolymers (PB-b-PDMS). These model block copolymers were obtained by anionic polymerization (high vacuum techniques) using 1,3-butadiene and hexamethyl(ciclotrisiloxane) monomers, sec-butyl lithium as initiator, and sequential addition. The SAXS analysis of a selected sample  reveals the existence of order-order and order-disorder transitions. At room temperature, the PB-b-PDMS copolymer presents SAXS peaks characteristics of hexagonally packed cylinders. As the temperature increased above 50 °C a transition from hexagonally packed cylinders to body centered cubic packing (bcc) can be detected.