EMAT SEMI FINAL QUIZ 3

What happens to thermoplastics when exposed to high temperatures?

• They soften and can be reshaped

• They become brittle and shatter

• They resist deformation

• They oxidize and rust

Thermosetting plastics are characterized by which of the following?

• They can be reheated and reshaped multiple times

• They permanently set into shape after the first heating

• They are highly flexible at all temperatures

• They are primarily used for single-use items

Elastomers are best described as:

• Materials that melt upon heating

• Rigid and brittle materials

• Polymers that can stretch and return to their original shape

• Polymers that cannot absorb moisture

Which of the following is an example of a natural polymer?

• Polyethylene

• Epoxy resin

• Rubber

• Nylon

Fiber-reinforced composites are typically used for:

• Electrical insulation

• Structural applications that require high strength and low weight

• Components exposed to extremely high temperatures

• Applications that need low tensile strength

Which of the following best describes the structure of a polymer?

• Random arrangement of metal atoms

• Long chains of repeating molecular units called monomers

• A lattice structure of crystals

• A single unit molecule with no repeating elements

How does high temperature affect thermoplastics?

• They become more brittle

• They corrode easily

• They soften and deform

• They become stronger

Which type of polymer is most likely to resist deformation at high temperatures?

• Thermoplastics

• Elastomers

• Thermosets

• Crystalline polymers

What is the primary function of the reinforcement fibers in composites?

• To provide elasticity

• To absorb moisture

• To provide strength and stiffness

• To increase temperature sensitivity

Which environmental condition can cause brittleness in polymers used in the shipping industry?

• High humidity

• Low temperatures

• UV exposure

• Chemical exposure