A straightforward method to synthesize a,w-telechelic poly(dimethylsiloxane)s

M.M.S. LENCINA; C. MÜLLER; V. HANAZUMI; F.L. REDONDO; M.D. NINAGO; C. VITALE; M.A. VILLAR; A.E. CIOLINO

Sevilla

Simposio; Fifth International Symposium Frontiers in Polymer Science; 2017

Grupo Español de Polímeros

One of the goals of polymer chemistry is developing new methodologies for the controlled synthesis of polymers with predictable, well-defined structures. Living anionic polymerization provides one of the best methodologies for synthesizing complex macromolecular structures such as a,w-telechelic polymers. These bifunctional macromolecules are obtained by different synthetic methods, which usually involve the titration of alkyllithiums over double diphenyl ethylene derivatives (DDPE). In this work we report the synthesis of a,w-telechelic PDMS by employing a novel bifunctional initiator, obtained from a commercial available siloxane precursor, diglycidylether terminated poly(dimethylsiloxane) (PDMS-DGE). The synthetic strategy involves the high-vacuum reaction of PDMS-DGE with sec-Bu-Li+ (to promote the nucleophilic ring-opening of oxirane rings) and the subsequently addition of diphenylethylene (DPE). The resulting bifunctional initiator was then employed to polymerize hexamethly(cyclotrisiloxane) (D3) by employing the conventional anionic polymerization reported in the literature. By using chlorosilane chemistry, silane (-SiH), vinyl (-CH=CH2), trimethyl and even methacryloyl ended PDMS were obtained. Narrow molar masses distributions (Mw/Mn < 1.3) and good control over the resulting number-average molar masses were obtained by SEC. In addition, 1H-NMR and FTIR characterization confirmed the presence of the targeted functional groups in the resulting polymers.