Siloxane oligomers, reactive

For viscosity adjustment of crosslinkable siloxane oligomers reactive monomers are added. Thus, the viscosity of the siloxane oligomer at 80°C can be reduced from 15 Pa s to 1 Pa s (Fig. 7). 

The main factors determining the reactivity of these siloxane oligomers towards other reactants are the type and nature of the terminal functional groups. Due to the fundamental differences in their structures, chemical reactivities and overall properties,... 

General structure of the (Si—X) terminated siloxane oligomers and a list of important reactive functional end groups (X) are given in Table 2. 

In both of the above techniques the reactive end-groups on siloxane oligomers were directly bonded to the terminal silicon atoms [i.e. Si—Cl and Si—N(CH3)2 respectively]. Therefore the resultant siloxane carbonate copolymers contained (Si—O—C)... 

Siloxane-acrylate copolymers Siloxane-p-methylstyrene copolymers 29 Siloxane oligomers, see reactive siloxane oligomers... 

As expected, the terminal functional groups mainly determine the reactivity of these siloxane oligomers towards other reactants. The variations in the backbone composition have critical effects on the glass transition temperature, solubility parameter, thermal stability and surface behavior of the resulting oligomers(12,13). 

---