How to Choose a Silane Coupling Agent
All silane coupling agents with three OR groups on silicon should bond equally well with an inorganic substrate. Our brand product line includes a variety of organofunctional alkoxysilanes.See Figure 6.Matching the organofunctional group on silicon with the resin polymer type to be bonded will dictate which silane coupling agent should be used in a particular application.
The organic group on the silane can be either a reactive organic group (an organofunctional group), or it can be a non-reactive organic group. The groups can be hydrophobic or hydrophilic, with varying thermal stability characteristics.
The solubility parameters of the groups will vary, depending on the organic structure; this will influence,to some extent, the interpenetration the polymer network will have into the siloxane network of the surface treatment. Table 1 lists some of the characteristics for common organic substituents attached to silicon. The choice of silane should nvolve matching chemical reactivity, solubility characteristics, structural characteristics and, possibly, the thermal stability of the organosilane with the same parameters in the polymer structure.