Synthesis of polydimethylsiloxane microemulsions by self-catalyzed hydrolysis/condensation of dichlorodimethylsilane |
| |
Authors: | Guillaume Palaprat Franois Ganachaud |
| |
Institution: | Laboratoire de chimie des polymères, UMR 7610, CNRS–université Pierre-et-Marie-Curie, tour 44 E1, 4, place Jussieu, 75252, Paris cedex 05, France |
| |
Abstract: | The preparation of PDMS microemulsions was carried out by adding at controlled rate dichlorodimethylsilane (DCMS) in a solution of sodium dodecylpolyoxyethylene(8) sulphate. The instantaneous hydrolysis of DCMS and subsequent condensation of the corresponding dihydroxysilane generate dispersions of cyclosiloxanes of small lengths (4 to 6 D units). The high load of chloride ions released during the hydrolysis step requires the presence of the above-mentioned electrosteric surfactant to avoid rapid coagulation of the dispersion. In addition, its sulphate end-group captures a proton that catalyses the ring-opening polymerization of cyclosiloxane as well as the polycondensation of disilanol PDMS chains. Final particles exhibit a diameter of about 50 nm for a polydispersity index of less than 1.1. They are constituted of PDMS chains exclusively linear (
;
) and of small cycles in low contents (less than 5 wt% in the best conditions). To cite this article: G. Palaprat, F. Ganachaud, C. R. Chimie 6 (2003). |
| |
Keywords: | dichlorodimethylsilane PDMS microemulsions ring-opening polymerization polycondensationdichlorodimé thylsilane microé mulsions PDMS polymé risation par ouverture de cycles polycondensation |
本文献已被 ScienceDirect 等数据库收录! |
|