Polymers can be natural or synthetic, but they have one thing in common: they’re composed of a series of repeating units (each known as a monomer) arranged in long chains and bonded together chemically. Most people think of plastics in association with polymers, but they are also found in DNA, proteins, cellulose and rubber. Charles Goodyear created the first synthetic polymer by accident in the 19th century, resulting in vulcanized rubber. Leo Baekeland had success with phenol and formaldehyde in the early 20th century, forming “Bakelite”. These early breakthroughs led to a spate of scientific experiments with polymers and exciting discoveries continue to revolutionize every industry out there from fashion to medicine, automotive and aerospace.
DNA is made of repeating units of nucleotides containing a sugar, a phosphate group, and nitrogen-based nucleobases.
Physical and Chemical Properties
Polymers are incredibly varied in their natural occurrence or synthetic production, and so the physical and chemical properties are boundless. These can be further expanded using additives. Generally, polymers are lightweight in comparison to metals and other elements. They are chemically resistant, good insulators of heat and electricity, flexible, or can be made more flexible with additives. Many polymers are based on petroleum, and some can be used to mimic natural materials. Synthetic polymers are not usually biodegradable, but more and more polymers are being recycled or converted into electrical energy today than ever before. Of the synthetic polymers, linear polymers can be recycled, whereas thermosets degrade when re-heated.
Production and Processing
When chemical bonds form between monomers to form a chain of molecules, the process is known as polymerization. This occurs by exposing certain materials to a specific pressure, heat, and/or catalysts. Here, the possibilities are endless: researchers are constantly manipulating the polymer’s molecular structure and introducing additives to widen the product range and scope of usage. Two classifications of polymerization exist: endothermic condensation polymerization and exothermic addition polymerization. Five methods are used to facilitate polymerization: gas-phase, suspension, bulk, emulsion or solution polymerization.
Electronics, packaging, vehicles and construction, medicine and fashion-- polymers are everywhere. Synthetic polymers are used to manufacture plastic bottles and bags, water pipes, cable insulation, ropes, crates, packaging, coatings, shape memory products, medical dressings, dental fillings, synthetic fabrics, sealants, adhesives, sheeting, films, vinyl and laminates. You’ll find natural polymers in clothing, rubber, hydrogels and medicines, among other things. Since designer polymers can be created with just about any desired physical or chemical property, potential applications of polymers are limitless.