Properties of polymethyl hydrogen siloxane
In addition to the general properties of dimethyl silicone oil, methyl hydrogen silicone oil
can participate in various chemical reactions due
to its active Si-H bond in its molecular structure, and has good film forming
properties. It can react with water or alcohol in the presence of a substance
such as a base or an acid to release hydrogen. In the presence of platinum
chloric acid, it is highly susceptible to an addition reaction with an olefinic
compound. When the temperature is greater than 50 ° C, it can be reacted with
the epoxy group-containing compound. Methyl hydrogenated silicone oil is not as
heat resistant as dimethicone, but its hydrophobicity and anti-stick properties
are better than dimethicone.
The methyl hydrogen silicone oil can be prepared by the following reaction.
A calculated amount of a mixture of methyldichlorosilane,
trimethylchlorosilane, and benzene was added to a reactor previously filled
with water. After the addition was completed, stirring was continued for 1
hour, and the layers were allowed to stand, and the acid water was discharged.
The oil layer is washed with water to neutrality. The telomerization reaction
is then carried out at room temperature in the presence of concentrated
sulfuric acid. After the reaction is complete, the sulfuric acid is removed and
the oil layer is washed again to neutrality. The low-boiling substance is
distilled off under reduced pressure, and decolorized with activated carbon, and
vacuum-filtered to obtain a finished product.
Methyl hydrogenated silicone oil can be crosslinked at low
temperatures. It has a good hydrophobic effect on the surface of various
substrates, a large contact angle, and a durable waterproof film, which is
widely used in textile, paper, leather and construction industries. Treating
the fabric with methyl hydrogenated silicone oil not only improves its tear
strength, abrasion resistance, wrinkle resistance and antifouling properties,
but also greatly improves the resistance to ironing and sewn, and can achieve
the original gas permeability without loss and is completely waterproof. In
addition, methyl hydrogen silicone oil has better anti-stick properties than
dimethicone. Therefore, it is widely used as a release agent for release
agents, paper and packaging materials in the rubber and plastics industries.
For example, a rubber product factory uses methyl hydrogenated silicone oil as
a car inner tube release mold, which can be used continuously for 1 to 2 weeks.
The optical glass coated with methyl hydrogen silicone oil not only has
excellent light transmittance, but also has excellent mold and moisture
resistance. Methyl hydrogenated silicone oil can also be used as a rust
inhibitor for metals.