What Is Polyester?

Are you asking yourself, "what is polyester?" The word “polyester” gives you flashbacks of the 70’s, you’re not alone. But those funky disco duds make up a very small percentage of what polyesters are used for. In fact, a great deal of polyester isn’t used for fabric at all.

So what is polyester? A deep understanding of the substance requires a bit more knowledge than most people have.  If you look at the word “polyester” it’s easier to break down. The prefix “poly” means more than one, or many. And according to Merriam-Webster, an “ester” is “an often fragrant organic compound formed from the reaction of an acid and an alcohol.”

So how do you get from a fragrant chemical combo to "Saturday Night Fever"? Well, it appears that certain ester groups are attracted to each other in different ways. And when they hook up by natural or synthetic means, they can make a multitude of combinations.

And here a bit of science class is the only way to go. To get the combination most often associated with the name “polyester” you mix ethylene glycol and dimethyl terephthalate. These make bisterephthalate, which is heated to become polyethylene terephthalate. (Kids don’t try this at home! The gassy byproduct is a bit hazardous to your health.) This final combination is better know to laymen as “PET”, which most people have seen stamped on the bottom of  drinking bottles.

 Yes, you read right, the same stuff used in many plastic bottles is also made into that famously fab, ultra-durable fabric you most associate the term "polyester" with. In the form of Mylar, it's also sandwiched with aluminum foil to create those shiny balloons you find at hospitals and birthday parties. But it doesn’t stop there. Other end products of polyester fiber are carpets, upholstery, rope, fiberfill, and sails, just to name a few. 

Even the polyester used in fabric has gone through a major metamorphosis since the stiff, scratchy stuff of the 70’s. Those “Polar fleece” blankets you curl up under in the wintertime? They're just a napped form of PET.

So while disco may be dead, the fiber that built the leisure suits lives on. Though you may not recognize it, polyester is all around. And you are likely to be using it, in some form or another, for a long, long, time.

Resource:

http://www.pslc.ws/macrog/pet.htm