Part 11: polymers Flashcards
What’s the difference between saturated and unsaturated polymers
Saturated polymer structures contain only single bonds. Unsaturated polymers contain at least one double or triple bond.
Define what a monomer is:
A monomer is a single molecule from which a polymer is synthesized. Monomers combine with other monomers to create a polymer
What is the difference between thermoplastic and thermosetting polymers?
Thermoplastic polymers have minimal cross linking and soften when heated. These are ductile.
Thermosetting polymers have at least 10% of units with cross linking and do not change in hardness with heat. These are brittle.
What is a copolymer
A polymer using two or more different monomers
Name the 7 types of polymers
- Plastics
- Elastomers
- Fibers
- Coatings
- Adhesives
- Films
- Foams
What are fibers used for?
Textile industry, has high tensile strength
What are coatings used for?
Coatings protect a surface. Can improve its appearance or electrically insulate.
What are adhesives used for?
Bond surfaces together
What are some properties of films?
- Thin object
- Low density
- High flexibility
- Resistant to moisture and some chemicals
What are foams used for?
- Cushions on seats and furniture
- Thermal insulation
What are the steps of addition polymerization?
- Initiation: add catalyst to a monomer
- Propagation: monomers combine to form a chain
- Termination: monomer is done combining
How does condensation polymerization work?
An OH and H branch on two monomers combine to form H2O molecule and a bond between the two monomers
Name three methods of forming polymers:
- Compression molding
- Injection molding
- Extrusion
What method is used to form fibers?
Spinning
Name two 3D printing methods for polymers:
- Fused deposition modelling: filament is melted onto surface and hardens after cooling
- Continuous liquid interface production:
