A Professor Plastics Feature ArticleSee Other Articles
Have you ever thought about what your hair conditioner, your car windshield, and cooking tools may have in common? OK, probably not, but I have. All these products can be made with silicones. These polymers are so versatile that you can find them in countless everyday products—from the practical, such as caulks and spatulas, to the purely fun, such as the Silly Putty™ that you played with as a kid. (And that I still play with.)
Although these polymers aren’t typically referred to as plastics (which is hurtful to me as Professor Plastics), they share many similarities. The true name for these materials is polysiloxanes, another one of those plastic “poly” words like polyethylene, polystyrene, polyvinyl chloride, etc. But let’s just use the common term: silicones.
As Professor Plastics, I believe that all polymers are marvels of modern chemistry, and I love each of them equally. Truly, I do. And yet, silicones hold a special place in my heart due to their unique molecular structure. (I can feel polypropylene getting jealous now.) You see, while the backbone of many modern polymers is carbon, silicones are built primarily with atoms of silicon—that’s right, the same element used to make glass.
That brings us to the really exciting part: silicones exhibit properties common to both glass and plastics. Like glass, they resist moisture, stand up to extreme temperatures, and don’t react with most materials. Like plastics, they are lightweight, strong, and able to assume many forms.
Not convinced that’s really exciting? Well, think about this: they’re so versatile that you probably use them multiple times a day. Depending on their composition, silicones can vary from liquid to gel to rubbery to hard. So they’re used in a broad range of products, including electrical insulation, consumer electronics, household appliances, automobiles, aerospace, medicine, clothing, and much more.
A special quality I love most about silicones is one they share with many other polymers: they offer a wide variety of important environmental benefits. Here are some examples:
- Alternative energy: Because of their ability to withstand long periods of sun exposure, silicones are used throughout solar cell manufacturing and installation. And durable silicone adhesives are used to bond the rotary blades of wind turbines so they can stand up to constant cycling for years and years.
- Construction: Thanks to their insulating and adhesive properties, silicone sealants play an integral role in improving energy-efficiency in buildings, where they’re used to prevent unwanted airflow, helping indoor spaces stay cool in summer and warm in winter.
- Waste reduction: Silicones are used to make and protect a wide range of products, including washing machines, army tents, personal computers, and auto parts. Silicones help these products last longer and perform better—when they last longer, we create less waste because we don’t have to replace them as often.
- Recycling: Recyclers use silicone technology to remove inks and envelope adhesives from paper. Silicones are gentle on paper, allowing it to retain its fiber strength so it can be used to make new paper products.
- Denim processing: Silicones can help reduce the amount of energy, water, and other resources needed to make our blue jeans. For example, today’s jeans are soft and wearable even when they’re new—a new silicone softening technology allows manufacturers to combine processing steps, which can save about 15 liters of water for each pair of jeans.
Innovative, practical, versatile … plus all the potential environmental benefits. Do you love silicones yet?