For many years, most of the silicone rubber manufacturers only focus on promoting their products, rather than explaining how silicone rubber is made and what are its components, but the general processes and raw materials of the silicone rubber should be known by clients.
First, let’s start with Vinyl Silicone fluid. Vinyl Silicone Fluid is a kind of polysiloxane, which contains 2 or more than 2 -Si-CH=CH2. It is the main ingredient of silicone rubber. By adding Vinyl Silicone Fluid, it could change silicone rubber’s crosslink density and therefore enhance the tear and tensile strength as well as hardness.
Major components of platinum cure silicone rubber
1. Silicone Base
The silicone base is mostly Polydimethylsiloxane which contains 2 or more than 2 -Si-Ch=CH2. Normally, it is a type of linear Polysiloxane that brings each Vinyl at each end. (If brings only one Vinyl in one end, it calls Vinyl silicone oil )
2. Crosslinker
The crosslinker is a kind of Organic silicon oligomer which contains 3 or more than 3 -Si-H, also called methyl hydrogen silicone oil. It is one of the basic components of platinum cure silicone rubber.
3. Platinum Catalyzer
There are many catalyzers that could initiate the Si-H reaction in Addition cure silicone rubber, but only the Platinum catalyzer is the most efficient. By applying the Platinum catalyst, the platinum cure silicone rubber could be vulcanized in room temperature. And by adding the proper ratio of inhibitor into the catalyzer, it could prolong the reaction speed and control the vulcanization.
4. Reinforce Fillers
Silicone rubber made by Vinyl Silicone Fluid and Hydrosilicone Fluid only do not have good mechanical properties, which means its tear and tensile strength, elongation, etc are not good. In order to improve its mechanical properties, reinforce fillers should be added. These filters normally are fumed silica, precipitation silica, silicon powder…If you want to get the clear silicone rubber, Methyl vinyl MQ silicone resin will be added to improve clear silicone’s mechanical properties.
5. Other additives
Other additives are added with the purposes of getting different colors, thermal conductivity, flame resistance, electrical conductivity, thermostability, transparency, etc.
What is platinum silicone?
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