Synthetic materials are manmade materials formed by natural resources and natural resources are resources from nature (synthetic and natural are antonyms.) Examples of synthetic materials include polyethylene and nylon. Polyethylene is made from the natural resources: carbon, hydrogen, sometimes oxygen, nitrogen, sulfur, chlorine, fluorine, phosphorous, or silicon. Polyethylene is the world’s most common plastic. It is mainly used for packaging (plastic bags, plastic films, containers, bottles and many many others.) The reason so many people use Polyethylene is because it is a good insulator, it is almost unbreakable and is environment-friendly. Nylon is made from the natural resources: oil, petroleum, air and water. It is a plastic with super-long, heavy molecules built up of short, endlessly repeating sections of atoms, just like a heavy metal chain is made of ever-repeating links. Often used for cloth, packaging, hair combs and much more. It makes excellent fibers.
Polymers are compounds that are made of many small repeating units (monomers) bonded together. So synthetic materials are manmade macromolecule that are made of thousands of repeating units and natural polymers are polymers found in nature. In order for a synthetic material to form, a polymerization must happen. Which is a chemical reaction in which two or more molecules combine to form larger molecules that contain repeating structural units. During the reaction, monomers (the small units that make up a polymer) are the ones that bonds with other molecules.