Polymers are substances composed of extremely large molecules termed macromolecules, with molecular masses ranging from 104 to 108 amu. The macromolecules consist of many smaller molecular units, monomers joined together through covalent bonds. The molar mass of the polymer is quoted as an average molar mass. The more common polymers include acrylics, alkyds, cellulosics, epoxy resins, phenolics, polycarbonates, polyamides, polyesters, polyfluorocarbons, polyolefins, polystyrenes, silicones,and vinyl plastics, to name but a few. Starch, glycogen, and cellulose are all polymeric versions of the monomer glucose.
Natural rubber is a latex exudate of certain trees and composed of monomers called isoprene units.
The usefulness of latex was first discovered by Lord Mackintosh in Malaysia in the last century and provided the foundation of his waterproof rainwear empire. The temptation to improve upon nature has always been great and has rarely been resisted. CelluloidTM is highly flammable and today has been replaced by greatly improved synthetic polymers such as bakelite discovered in 1907 by the Belgian-American Chemist, Leo H. Baekeland. If the solution is forced instead through a narrow slit, a thin transparent film or sheet is obtained called cellophane. Click here for information on Thermoplasts versus Thermosetting here.