Classification according to structure and phenyl content: roughly divided into five grades: low phenyl silicone oil (phenyl content is 5-10% mole); Medium phenyl silicone oil (phenyl content is about 25% mole); High phenyl silicone oil (phenyl content is about 45% mole); Silicone oil with high phenyl content and low polymerization degree (phenyl content is more than 45% mole); Cross linked methyl phenyl silicone oil. The above phenyl content is generally expressed by the refractive index of the product in industry, for example, the refractive index of 30% phenyl content is about 1.51.
IOTA BJ550 Polyphenylmethyldimethylsiloxane -IOTA (phenylsilicone.com)
