Science and technology of silicone rubbers

Silicone rubbers have become an indispensable part of our daily lives and modern industry (Shit and Shah, 2013). Their success lies in their unique ability to combine high stretchability, flexibility, heat resistance, and chemical stability, among other properties (Han et al., 2022). This performance comes from their unusual molecular structure, which is based on a silicon-oxygen backbone, called siloxane (Seethapathy and Górecki, 2012). The structure, very different from the carbon-based chains found in most other types of rubbers and plastics, is a key factor in the performance of silicone rubbers. Understanding the siloxane particularities is crucial for their successful application in situations where many other materials fall short.

The development of silicone rubbers began in the middle of the 20th century, during a period of intense interest in silicon-based chemistry (Polmanteer, 1988). At first, they were mainly used for things like electrical insulation, where their thermal stability at high and low temperatures was a major advantage (Warrick et al., 1979). Over time, as manufacturing techniques improved and scientists learned how to fine-tune their properties, silicone rubbers started appearing in a wide range of products and industries. Today, they’re used in many applications, from medical implants to automotive parts and even in advanced technologies like robotics and wearable devices (Shit and Shah, 2013).

One of the things that make silicone rubbers so versatile is their ability to withstand extreme conditions. They stay flexible even in freezing temperatures and do not break down easily in high heat. This makes them especially valuable in industries like aerospace and automotive, where materials often must deal with harsh environments. Their resistance to UV light, weath- ering, and many chemicals also means they last long, even under the worst environmental conditions (Riaz et al., 2024).

Another significant advantage of silicone rubbers is that they can be customized to fit different needs. Manufacturers can create materials with very specific properties by adjusting their formulation and curing process (Mazurek et al., 2019). For example, in the medical field, silicone rubbers are used to make implants and prosthetics because they are safe for use inside the body (biocompatibility). Wearable devices’ softness and durability make them comfortable for people to wear all day. In robotics, their flexibility allows engineers to design parts that move naturally, mimicking human motions.

Silicone rubbers are not just used in high-tech fields; they are also part of everyday life. They are everywhere, from kitchen tools to car parts and even sports equipment (Utrera-Barrios et al., 2023). They are great at absorbing vibrations, and reducing noise, which makes them useful in cars, and industrial machines (Zhao et al., 2020). These everyday applications show how practical and reliable they are. In this sense, as technology and industry progress, silicone rubbers keep up by adapting to new challenges. This ability to change and improve is part of what has kept them relevant over the years.

Of course, silicone rubbers are not perfect. Making them takes a lot of energy, and they are not easy to recycle because their molecules are crosslinked. This structure, which gives them strength and stability, makes it hard for them to break down (Imbernon and Norvez, 2016). Researchers are working on solutions to these problems, such as finding ways to produce them using renewable resources or designing methods to recycle them more effectively (Furgal and Lenora, 2020; Rupasinghe and Furgal, 2022). These efforts are part of a growing push to make materials more sustainable and less environmentally harmful.

This chapter considers all these advantages and disadvantages to take a closer look at silicone rubbers, focusing on what they are made of, how they are cured, and why they work so well in many different applications. It also addresses the environmental and regulatory aspects that shape their future, emphasizing the importance of sustainability in ensuring their continued relevance.