The invention of Bakelite in 1907 ushered in a new era in human history – the era of synthetic materials. Synthetic materials are made by treating or combining existing materials to change their properties completely. Many of the synthetic materials we use today are derived from fossil fuels that have undergone chemical changes under extreme heat.
Whether you realize it or not, you are surrounded by synthetic materials. The phone or computer you are reading this article on is constructed almost entirely out of synthetic materials. This article is a quick guide to some of the most significant synthetic materials today.
Nylon is one of the most significant synthetic fibres ever created. The main reason for this significance? Nylon was the first ever synthetic fabric and ushered in a new age of manufacturing. Nylon is a polyamide material made by reacting carbons found in fossil fuels under high temperatures. Crude oil is heated in this way to form a polymer. The polymer is then melted and passed through thousands of tiny holes to form strings of nylon fabric. This fabric is highly resistant and structurally sound and can be used for making everything from toothbrushes to rucksacks.
Wallace Carothers devised the process for creating nylon in 1939. The material was quickly put into use, making stockings, parachutes, and military clothing during the Second World War.
Polyethylene is the most commonly produced plastic in the world. Over 80 million tons of this synthetic material are produced each year. It is primarily used for packaging but has many other uses due to its hardy nature and simplicity of production. All forms of polyethylene can be used to make injection-molded products. Injection molding is one of the most time-efficient methods of producing a resistant item. The material is waterproof and relatively hard to destroy, making it a danger to the environment if not recycled correctly. It is made by isomerizing ethane and propane.
Imperial Chemical Industries first produced this material in 1933. It has since found innumerable uses and pervaded human and animal lives in an unprecedented manner.
Rayon is a semi-synthetic fiber derived from trees. Tree fibers – usually eucalyptus or beech – are processed using a great deal of water and chemical washing before being strung out as rayon. This material is similar in texture to silk, and it is extremely strong like silk. This makes it perfect for producing high-stress fibrous products like tire walls. It is also used in some high-end sports clothing.
To make rayon, tree pulp is dissolved in caustic soda to convert it into alkali cellulose. It is then chemically treated with carbon disulfide to form a new compound. They are then spun into filaments which are bathed in acid, spun again, and then washed.
Kevlar is best known for being used in the construction of ballistic vests – being able to stop speeding bullets if layered and angled correctly in relation to other materials. It is also a highly heat-resistant material, leading to its use in the aerospace industry. Because of its hard-wearing high heat-resistance, high-end motorcycle safety clothing also usually contains large amounts of Kevlar, which tends to be a rather expensive material.
Kevlar was invented in 1964 by the American chemist Stephanie Kwolek. She was looking into ways of producing lightweight, hyper-tough tires. Kevlar is made by combining various chlorides and acids. This produces a low-viscosity liquid that can be run through a spinneret to create a workable material. Interestingly, the ultraviolet radiation that is part of sunlight degrades the resistant capabilities of Kevlar over time. This has led to almost all Kevlar in use outside – such as the Kevlar used in body armor – to be treated or hidden with material that protects it from the Sun.
PVC – standing for Polyvinyl Chloride – is the third most produced synthetic material in the world. It is used for construction, clothing, and many other applications. Polyvinyl Chloride is largely used as a replacement for natural rubber. The natural rubber must be harvested from trees and is extremely labor-intensive. PVC has comparable properties but can be synthesized easily. It was first synthesized in 1872 but was not considered a commercial success until the BC Goodrich company plasticized it in the 1930s.
These are five of the most common synthetic materials that are available, and how they are processed into useable materials. Perhaps there are some that you are unfamiliar with, or even use every day, and maybe even some applications of some materials you had not considered before.