ADSORPTION STUDIES OF DIFFERENT END-FUNCTIONALIZED LINEAR POLY(DIMETHYLSILOXANE)

The adsorption of end-functionalised poly(dimethylsiloxane) (PDMS), of both low and high molecular weight, on to silica and alumina from car bon tetrachloride has been investigated by Fourier transform infrared spectroscopy. It was found that the adsorbed amounts of these end-func tionalised PDMS depend strongly on the composition of the polymer; sam ples with end groups having a high surface affinity were found to adso rb to a greater extent. Detailed information on the structure of the a dsorbed layer obtained by the Scheutjens-Fleer theoretical model and a Monte Carlo simulation indicated that polymers with such end groups a dsorb primarily as loops, with fewer segments in trains and tails comp ared with a homopolymer. Adsorption was found to be greater on alumina than on silica for both molecular weight series.