Polydimethylsiloxane (PDMS) oil and crosslinked rubber react with hydroxylated surfaces, when heated at 250-300°C. PDMS is thus chemically bound to silicate glass sheets and to iron hydrous oxide particles. As a result, stable and adherent PDMS coatings may be obtained over glass, by heating silicone oil spread over glass sheets. Glass-PDMS-glass adhesive joints can also be obtained by heating preformed, crosslinked silicone sheets between glass parts. Also, PDMS rubber is heat-stabilized by in situ-generated iron hydrous oxide particles. These results are explained by considering that active Si-O chain ends, formed by chain scission, bind to surface hydroxyl groups, in a reaction competitive with the formation of cyclic oligomers. PDMS can thus be seen as a thermally-activated, reactive adhesive.