Chemistry Basics
This is the smallest unit of an element that retains the element's identity.
What is an atom?
These small molecular units join together to form polymers.
What are monomers?
This property describes how much mass is contained in a given volume.
What is density?
This abbreviation identifies the polymer polyethylene terephthalate, commonly used for beverage bottles.
What is PET?
This manufacturing process forces molten or softened plastic into a mold to create a product's shape.
What is injection molding?
These positively charged particles are found in an atom's nucleus.
What are protons?
This term describes a large molecule made of repeating molecular units.
What is a polymer?
Polymer chains with this shape may pack more closely than heavily branched chains.
What are mostly straight chains?
This property measures a material's ability to withstand sudden impacts without breaking.
What is impact resistance?
Manufacturers monitor this variable to help plastic flow properly during molding.
What is temperature?
An atom with equal numbers of protons and electrons has this overall electrical charge.
What is a neutral charge?
This process occurs when monomers connect through chemical bonds to form repeating structures.
What is polymerization?
This mechanical property describes a material's ability to resist being bent or deformed.
What is stiffness?
This type of polymer forms a rigid, cross-linked network during curing and generally cannot be remelted and reshaped like a thermoplastic.
What is a thermoset?
This PET bottle manufacturing process uses a preform that is reheated, stretched, and blown into a mold.
What is injection stretch blow molding?
This type of chemical bond forms when one atom transfers electrons to another, creating oppositely charged ions.
What is an ionic bond?
These molecular connections link polymer chains together and can affect rigidity and heat resistance.
What are cross-links?
This property allows a material to stretch or deform and then return toward its original shape.
What is elasticity?
This type of material failure occurs when a plastic breaks with little deformation beforehand.
What is brittle fracture?
A manufacturer uses this approach when comparing processing requirements, strength, stiffness, and wear resistance before choosing a plastic.
What is material selection?
In this state of matter, particles remain close together but move past one another.
What is a liquid?
This type of polymer can generally be heated, reshaped, and cooled repeatedly.
What is a thermoplastic?
These three structural factors can help explain why a rubber band stretches while a plastic ruler remains rigi
What are chain structure, cross-linking, and molecular interactions?
Ultraviolet radiation from this natural source can damage polymer chains and make some plastics more brittle.
What is sunlight?
These three process variables can be evaluated to help correct thin walls and weak spots in plastic bottles.
What are temperature, pressure, and material flow?