Just imagine a world without plastics. Although they are now a part of our daily lives, plastics are a relatively recent arrival on the chemical scene. These synthetic materials only began to enter our lives in a major fashion some seventy years ago. But they quickly captured peoples' imagination. Plastic Man, who could extend his arm to catch criminals, became an immediate hero! Of course, he was fictional. Today, though, we have real materials which before the Second World War could only be dreamed of. The raw material for most plastics derives from petroleum. But it is the ingenuity of the modern chemist that really makes plastics possible. The secret lies in taking the molecules derived from petroleum and linking them together to make the giant molecules, or "polymers," that characterize all plastics. The earliest plastics were actually just modifications of some naturally occurring polymers such as cotton. Treating cotton with a mixture of nitric and sulfuric acids yielded the first "miracle material," christened "celluloid." It could be molded to make all kinds of interesting objects ranging from combs, to billiard balls, to washable collars. The only problem with celluloid was its high flammability. Today, just about the only use for celluloid is in the making of ping-pong balls! No other plastic can quite match celluloid's bounce.
The first plastic that was not a modification of a natural substance but was made completely from scratch was "Bakelite," synthesized by Leo Bakeland in 1906. He found that mixing phenol and formaldehyde yielded a hard, useful synthetic. Early radios and black telephones were made of Bakelite. The pivotal moment in the development of modern plastics, however, occurred in the 1930's with the synthesis of nylon by the American chemist Wallace Carrothers. Combining hexamethylene diamine and sebacyl chloride instantly forms nylon, which can be drawn out like a fiber. Today we jump out of planes with nylon, scrape our windshields with it and even fasten our shoes with it. Velcro! Little nylon hoops and hooks which make life easier on earth and in space. There are some 250 meters of velcro tape used on each Space Shuttle mission to prevent objects from floating around. Other plastics we use regularly include polyvinyl chloride for vinyl raincoats, vinyl car seats, vinyl water pipes and vinyl balls. Polyethylene gives us bags to put our groceries in, hula hoops for exercise and plastic joints to replace a damaged hip. Polycarbonates like Lexan are super hard and give us roller blade wheels and almost unbreakable glassware. Some polymers, like the polyesters, can either be drawn into fibers or molded into various shapes such as bottles. Because polyester is so much lighter than glass, shipping costs are reduced. The polyester can even be recycled into clothing! It is an environmentally friendly material. True, not everything about plastics is rosy. Small amounts of their component chemicals can leach out and end up in the environment. Some of these have hormone like properties and have been accused of impairing our health. While there may be something to this, there is just no doubt that the benefits of plastics greatly outweigh any of the problems they present. If you don’t believe me, just try to go through a day without using some sort of plastic. I’ll wager you can’t.