Chemists call the small building blocks of a plastic by the name monomers. When they link two different monomers together, they arrange them in several unique patterns. A random copolymer has no set order for its different starting building blocks.
An alternating copolymer strictly switches the two pieces in a perfectly repeating pattern. A block copolymer features a long chain of the first monomer attached to the second. A graft copolymer features a main backbone of one piece with side branches of another.
Students sometimes confuse a copolymer with a simple physical mixture of two different plastics. In a physical mixture, the separate plastic strands just tangle together like cooked noodles. In a true copolymer, the different molecules connect together through permanent chemical bonds.
This chemical bonding allows chemists to carefully tune the physical properties of the material. They can blend the useful traits of two totally different plastics into one single item. One starting monomer might provide tough strength while the other monomer provides bouncy flexibility.
Adjusting these chemical ratios creates endless new possibilities for advanced commercial materials. This process is a major strategy in modern polymer engineering and industrial manufacturing.