Preparation and properties of functionalized polyorganosiloxanes

Abstract

Abstract A series of linear functionalized polyorganosiloxanes of the type Me 3 SiO[MeSiO(CH 2 ) n R] x (Me 2 SiO) y SiMe 3 , where n = 2, R = —(CH 2 )NMe 2 ; n = 1, R = —(CH 2 )OEt; n = 4, R = —(CH 2 )COOEt; n = 3, R = —(CH 2 )Me, have been prepared and characterized. Functional group loadings of ∼4 mol % ( x = 1, y = 25), ∼11 mol % ( x = 3, y = 23), and ∼30 mol % ( x = 8, y = 18) were obtained by reacting commercially available copolymers Me 3 SiO(MeSi{H} O) x (Me 2 SiO) y SiMe 3 with the appropriate ratios of x : y , with the required quantities of HO(CH 2 ) n R , using dichloro(1,5‐cyclooctadiene)platinum(II) as catalyst. Amine, ether, ester, and alkyl functionalized siloxanes were obtained in good yields after purification, and each fluid polymer has been characterized by 1 H and 13 C‐nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectral measurements, elemental analysis, viscosity, surface tension, and density measurements. The functionalized polymers exhibit Newtonian behavior over the range of shear rates 0.4–79.4 s −1 , and significant viscosity enhancements were observed for all functionalized polymers compared with poly(dimethylsiloxane) fluids of similar chain lengths. The functionalized siloxanes exhibited in almost all cases an increase in both viscosity and density as the functional group loading increased. The surface tensions of the polymers have also been determined and lie within the range 18.8–22.3 mN m −1 . © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 808–817, 2001