Platinum Cured vs. Peroxide Cured Silicone Rubber: What’s the Difference?

You can cure silicone in various ways. And the method you choose depends on what you want to get out of your end product. Two of the most widely used curing methods are platinum curing and peroxide curing.

So what exactly is the difference between these two curing methods? What are their strengths and weaknesses? Which one is better for your application? Read on to learn about all of these and more.

1. What is Silicone Curing? How Does It Work?

Many silicone products used in various industrial functions need to be in a solid state. As you know, uncured silicone takes the form of a highly-adhesive, viscous gel. You need a way to convert it into a solid material. That’s where silicone curing comes in.

During the curing process, the synthetic silicone is chemically cross-linked via a curing agent. Two of the most widely used curing agents are peroxide and platinum. 

These two reagents differ in terms of chemical properties. And the properties you get for your end product depend on which curing agent you apply.

2. What’s The Difference Between Peroxide and Platinum-Cured Silicone Rubber?

Peroxide-cured silicone products are considered conventional. But platinum-cured silicone has been increasing in popularity. Let’s go in depth into these two resulting products to see how they differ.

2.1 Platinum-Cured Silicone Rubber
The Platinum Cure Process
This curing method is also known as the addition system. That’s because it undergoes an addition reaction to produce the desired polymer.

Platinum acts as the catalyst, producing a reaction from the raw siloxane polymer. This reaction creates an ethyl bridge between the platinum catalyst and the polymer. In other words, it creates a cross-link in the polymer chain.

In contrast to peroxide curing, platinum curing has zero byproducts. It also has a faster curing time.

Platinum-Cured Silicone Rubber: Advantages
Platinum-cured silicone rubber is widely considered the “cleaner” choice. Unlike peroxide curing, which produces volatile acids, platinum curing results in no byproducts. This makes platinum-cured silicone preferred for food and medical applications.
It has better visual clarity and transparency. These qualities make it suitable for when see-through visibility is a requirement.
Platinum-cured silicone is superior in a number of desirable properties. These properties include higher levels of tensile strength, elongation, and tear strength.
Platinum curing does not require the use of talc – a mineral that’s been linked to health issues.