Synthesis, Characterization, and Gamma Radiation Effects

A. J. SATTI; F. NADOR; C. VITALE; G. RADIVOY; N. A. ANDREUCETTI; A. E. CIOLINO; E. M. VALLÉS

JOURNAL OF APPLIED POLYMER SCIENCE

JOHN WILEY & SONS INC

Año: 2012 vol. 124 p. 832 - 839

0021-8995

Abstract. Anionic ring-opening polymerization (AROP) was employed for the controlled synthesis of linear model block copolymers of 1,3,5,7-tetrametil-1,3,5,7-tetravinyl(cyclotetrasiloxane) (V4) and 1,3,5-dimethyl(cyclotrisiloxane) (D3) monomers by using sec-butyl lithium (sec-BuLi+) as initiator, and high-vacuum anionic polymerization techniques. V4 copolymerization was promoted by using D3 and sec-BuLi+ producing living silanolates that open the stable V4 ring. For this purpose, two strategies were employed: a) sequential addition of monomers, and b) copolymerization at different reaction temperatures. According to the experimental results, higher levels of V4 incorporation (~ 18.14 mol %) were obtained by mixing both co-monomers and performing the reaction at high temperatures (80 °C). This strategy allowed the control of the V4 incorporation in the desired copolymers, giving access to the synthesis of model siloxane polymers with potential biomedical applications, which could be improved by chemical (hydrosilylation) or physical (irradiation) modifications.