A proper understanding of plastics in general begins with an understanding of their natural counterpart. The scientific term resin refers to specific types of organic compound mixtures that are not soluble in water. Resins are usually secreted by plants (especially woody plants) as a type of natural “bandage” to aid recovery when the plant has sustained harm in some way. These substances are very viscous, transparent to yellowish-brown in color, and flammable. They are notable – and have historically been economically valued – for being able to convert to arrangements of polymers (long chains of organic substances) and harden into solids.
At risk of oversimplification, plastics can simply be conceived of as synthetic versions of resins. Like natural resins, synthetic substances known as “plastics” comprise thick liquids which can harden under certain conditions. Although they share behavioral similarities with natural resins, it is important to note that plastics possess chemical makeups which are substantially different.