Silicone is a synthetic polymer that is made from the chemical element of silicon. While both silicone and silicon sound very similar they are two separate things. Silicon is the raw chemical element, whereas silicone is a rubber material. The link between the two is that silicone rubber is primarily derived from silicon, along with hydrogen, oxygen and carbon.
To make silicone rubber, the silicon atoms have to be isolated from the silicon dioxide compound known as silica. The isolation is done by heating a large quantity of quartz to temperatures as high as 1800°C. There are then multiple processes that follow.
Silicone rubber is one of the most popular rubber materials for a huge range of different industries. This is because it has so many benefits that make it the perfect material for a huge range of applications from extrusions to automotive parts. These advantages include:
Heat Resistance
One of silicone rubber’s most impressive advantages is its ability to withstand extreme temperatures, both high and low. The material’s temperature range is truly incredible; it can withstand and perform better than all other polymers when met with extremely high temperatures. Some components of silicone rubber can withstand temperatures of up to 305°C.
Its ability to withstand such temperatures allows the material to retain its structure and properties over a huge temperature range. In addition to its ability to perform at high temperatures its temperature range also allows the material to maintain its flexibility at temperatures as low as -70°C. This range from hot and cold performance is very rare and can only really be found in silicone rubbers.
Sterilisation
Silicone rubber is very commonly found in food and medical products. This is because silicone rubber has a non-porous nature which means that it will not be susceptible to a buildup of bacteria. Sterilisation and hygiene are such a huge matter in these industries and therefore having the most sterile and safe materials to use is hugely important.
There are also silver nanoparticles that can be blended into silicone which can act as antibacterial agents. These then work to prevent infestation of microbes like MRSA and e. Coli growing and multiplying on the product in which silicone rubber has been used.
Silicone is also an FDA-approved material which means that it has been specially formulated to meet the requirements of both the food and drug associations.
High tensile strength
For many reasons, silicone rubber can be used for far more applications than general-purpose silicones. One of these reasons is that the material was designed to have far better elongation and tear strength compared to the general-purpose grade. This helps the products that they are used in to be more resistant to abrasion and fatigue. Because of this, it is typically used in applications such as extrusions, moulding and calendering. This is because all of these applications involve the stretching and reshaping of the material so any tear strength or elongation weaknesses will result in the tearing of the material.
Low chemical reactivity
In many applications where chemicals are present, you will often find that silicone rubber is used. This is due to silicone’s low chemical reactivity. Unlike other rubbers, silicone does not have a carbon-to-carbon backbone, it has a silicone-to-oxygen backbone. This means that where other rubbers are susceptible to damage from ozone, chemicals, extreme heat and other potential hindrances, silicone rubber can comfortably withstand them.
Disadvantages Of Silicone Rubber
While silicone rubber has a huge number of advantages, as with most materials it does also have some disadvantages. The main disadvantages of silicone rubber are:
Tear strength
General purpose silicone rubber has very poor tear strength. This is because of the siloxane backbone (silicon to oxygen). While this backbone offers brilliant stability and flexibility it also has a very weak chain and can therefore be very much susceptible to tears. However, the general purpose silicone rubber can be strengthened into high tensile strength silicone rubber with the addition of other ingredients. High tensile strength silicone rubber is the complete opposite in the fact that the tear strength is extremely high and is designed to have far better elongation.
Cost
The biggest disadvantage to this material is the cost. It is more expensive than most of the other rubbers on the market.
While the initial investment may be slightly higher than with other rubber materials, the return on investment will be far greater thanks to their durability, long shelf life and all the other amazing benefits that we have talked about.
