Plastics Composition and Types

What type of polymerization involves the creation of water as a byproduct?

Which of the following statements about thermoplastics is NOT true?

Which type of plastic is characterized by a 3D network and strong connections between chains?

Which type of plastic is known for its ability to return to its original shape after being stretched?

Which of the following is an example of an amorphous plastic?

What distinguishes polyaddition from polycondensation?

Which type of plastic is known to be difficult to remelt and begins to decompose if attempted?

Which type of plastics can vary between being disordered and having a partially ordered structure?

Plastics Composition

Plastics are composed of carbon-hydrogen bonds.
Monomers combine to form polymers.
Two main polymerization reactions are polycondensation and polyaddition.

Polycondensation

Combines two or more different or identical substances.
A water byproduct is created, which must be removed.
Examples of plastics produced this way: polyester, polyether, polyamide.

Polyaddition

Combines two or more identical or different substances.
The atomic arrangement of the monomer is changed.
Requires a catalyst and high temperature/pressure.
No byproducts are created.

Types of Plastics

Classified into thermoplastics, elastomers, and thermosets.

Thermoplastics

Melt when heated.
Covalent bonds are relatively resistant to temperature changes.
Intermolecular bonds (like hydrogen bonds) weaken at higher temperatures. The strength depends on chemical or physical properties.
Generally plastic, deformable, and linearly shaped.
Can be amorphous (disordered, glassy, transparent, brittle) or semi-crystalline (partially ordered, crystalline, ductile, opaque).
Examples: PP (polypropylene), PE-HD (high-density polyethylene), PE-LD (low-density polyethylene), PE-LLD.

Elastomers

Soften at room temperature.
2D or 3D network with large meshes.
Strong connections between chains make them elastic and spring back after being deformed.
Examples: EPDM (ethylene propylene diene monomer).

Thermosets

3D network with strong connections between chains.
Harden chemically, and cannot be melted again without decomposition happening.
Resistant to high temperatures.
Examples: Bakelite, Melamine formaldehyde.
Often rigid and not easily scratched.

This quiz covers the fundamental concepts of plastics, including their composition, polymerization reactions such as polycondensation and polyaddition, and the classification of different types of plastics like thermoplastics, elastomers, and thermosets. Test your knowledge on the chemical properties and reactions involved in the creation and characteristics of plastics.