SiSiB silanes can be used as adhesion promoter (coupling agent) in HFFR material or filled rubber, to improve the mechanical and electrical properties of cables. In the presence of moisture the alkoxy groups OR of the silane bind to the filler surface, releasing alcohol as a by-product. The organofunction group Y binds to the polymer.
For more information on filler pretreatment, please visit our guide for filler treatment.
SiSiB Amino or Vinyl Silane Coupling Agents can:
Enable the high loading levels of ATH or MDH requrired for effective flame retartation
Improve the processability of highly filled polymers
Enhance the mechanical properties of the finished product
The choice of SiSiB silanes functionality for HFFR applications depends on the polymer. For the thermoplastic HFFR either vinyl or amino silanes may be used as adhesion promoter (coupling agent). When using vinyl silanes a small amout of additional peroxide is required to obtain adhesion.
For elastomeric HFFR compounds based EVA or EVA-polyolefin blends the choice of SiSiB silanes adhesion promoter depends on the vinyl acetate (VA) content of the polymer. Amino silanes are typical used when the VA content is higher than 20%, vinylsilanes are an alternative when the VA conter is lower than 20%.