What is the definition of "plastic"?
A material consisting of very large molecules characterized by light weight, high corrosion resistance, high strength-to-weight ratios, and low melting points. Most plastics are easily shaped or formed.

Learn more about plastic in the class Plastics 240 below.


Materials Training


Class Information
Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Plastics 240
Description:This class identifies the major categories, properties, and uses of plastics.
Prerequisites: 500100  500110 
Difficulty:Intermediate
Number of Lessons:17
Language:English, Spanish
 
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Class Outline
  • Objectives
  • What Is a Plastic?
  • Natural Polymers
  • Advantages of Plastics
  • Disadvantages of Plastics
  • Structure of Polymers
  • Polymer Arrangements
  • Types of Plastics
  • Thermoplastics
  • Types of Thermoplastics
  • Thermosets
  • Types of Thermosets
  • Elastomers
  • Types of Elastomers
  • Additives
  • Plastics in the Marketplace
  • Summary
  
Class Objectives
  • Define plastic.
  • Identify natural polymers.
  • Identify the positive properties of plastics.
  • Identify the negative properties of plastics.
  • Describe the molecular structure of a polymer.
  • Identify the possible arrangements of polymer molecules.
  • Identify the major types of plastics.
  • Describe the characteristics of thermoplastics.
  • Identify common types of thermoplastics.
  • Describe the characteristics of thermosets.
  • Identify common types of thermosets.
  • Describe the characteristics of elastomers.
  • Identify common types of elastomers.
  • Identify common additives.
  • Describe common uses for plastics.

Class Vocabulary

Vocabulary TermDefinition
additive Any substance that is added to a plastic during manufacturing in order to improve its properties.
butyl A type of elastomer that is often used to make airtight products.
chloroprene A type of elastomer that effectively resists oil, weather, heat, and flame. Chloroprene was one the first successful synthetic rubbers.
coefficient of thermal expansion The degree that a material increases in size as it increases in temperature.
coloring agent An additive that is used to change the color of a plastic.
corrosion resistance The ability of a material to resist deterioration or degradation due to surface exposure.
cross-linking The development of primary bonds that form between polymer molecules. Elastomers are slightly cross-linked; thermosets are heavily cross-linked.
elastomer A formation of a thermoplastic or thermoset that can stretch and then return to its original shape without permanent deformation. Elastomers are only slightly cross-linked.
electrical conductivity The ability of a material to conduct an electrical current.
ferrous metal Any metal that contains iron.
filler An additive that is used to partially replace a plastic material and reduce its cost.
macromolecule An incredibly large molecule that consists of repeating molecular units.
mer The basic molecular unit that combines in long chains to form polymers.
molecule The smallest unit into which a material can be divided without changing its properties. A molecule consists of a group of atoms held together by strong primary bonds.
natural polymer A polymer resulting from raw materials found in nature.
natural rubber A natural elastomer that is extracted as a sap from tropical trees. Natural rubber must be vulcanized for commercial use.
phenolic A type of thermoset known for its chemical stability and ability to maintain its desired dimensions.
plastic A material consisting of very large molecules characterized by light weight, high corrosion resistance, high strength-to-weight ratios, and low melting points. Most plastics are easily shaped or formed.
plasticizer An additive that is used to add softness and flexibility to a plastic in order to facilitate the manufacturing process.
polyester A type of thermoset that is commonly combined with other polymers for numerous commercial uses.
polyethylene A type of thermoplastic known for being both chemically inert and inexpensive. Polyethylene is the most popular commercial plastic.
polymer A material made of very large molecules that generally does not have a crystalline structure. Polymer is a more technical term for a plastic.
polypropylene A type of thermoplastic known for being very lightweight.
polystyrene A type of thermoplastic that is both transparent and easily shaped.
polyurethane A type of plastic that is often chemically complex. Polyurethane can be manufactured as both a thermoset and an elastomer.
polyvinyl chloride A type of thermoplastic that can be manufactured to produce both rigid and flexible materials.
primary bond A bond that forms between atoms and that involves the exchanging or sharing of electrons.
secondary bond A bond that involves attraction between molecules. Unlike primary bonding, there is no transfer or sharing of electrons.
shellac A resinous substance secreted from a particular beetle that is used to coat floors and furniture. Shellac is a natural polymer.
silicone A type of thermoset known for being both heat resistant and water repellant.
stabilizer An additive that is used to help prevent a plastic from breaking down due to exposure to adverse environments.
steel A metal consisting of iron and up to 2.11% carbon, usually with small amounts of manganese, phosphorus, sulfur, and silicon as well.
strength-to-weight ratio The relationship between a material's strength and its weight. Materials that are light but also very strong have a high strength-to-weight ratio.
synthetic polymer A polymer that is chemically manufactured from separate materials. Synthetic polymers require human intervention.
thermal conductivity The ability of a material to conduct heat.
thermoplastic A type of plastic that can be softened by heat, hardened by cooling, and then softened by heat over and over again. Thermoplastics are not cross-linked.
thermoset A type of plastic that is permanently hardened by cooling. Thermosets are heavily cross-linked.
vulcanization A manufacturing process that uses additives and chemicals along with heat and pressure to increase the number of cross-linked bonds in an elastomer. Vulcanization adds strength and toughness to a rubber.