Product Description

CAB-O-SIL® M-7D is the densified form of CAB-O-SIL® M-5fumed silica — a medium-high surface area grade developed specifically to reinforce silicone rubber. Its higher bulk density (versus standard M-5) allows for faster incorporation and easier handling in production, at the trade-off of requiring very high shear dispersion equipment to achieve adequate dispersion in the polymer matrix.

Like all untreated CAB-O-SIL® fumed silicas, M-7D is characterized by:

● High purity

● Aggregated structure

● Submicron particle size

● Low bulk density

● Hydrophilic surface

Application

CAB-O-SIL® M-7D is suitable for reinforcing silicone rubbers, including heat-cured rubber, high-temperature vulcanizing or high-consistency rubber (HTV/HCR), and liquid silicone rubber (LSR) — increasing hardness, tensile strength, and elongation in the finished part.

Because M-7D has a hydrophilic surface, further surface modification (e.g. in-situ treatment during compounding) is necessary to prevent crepe hardening in silicone rubber compounds over storage time.

With a densified, higher-bulk-density silica like M-7D, very high shear dispersion equipment is recommended to achieve adequate dispersion. In exchange, the higher bulk density gives faster wet-in and incorporation into viscous polymer systems compared with standard, low-bulk-density fumed silica grades.