Plastics Flashcards
What are the three states of fluids and solids?
Viscous, Visco-elastic, Elastic
What are the three Polymer Synthesis methods?
Polymerization, Polycondensation, and Polyaddition
What are the three types of polymerization?
Radical, Ionic, Coordinative
What are some examples of polymers formed by polymerization?
- Polyvinyl Chloride
- Polyethylene
- Polystyrene
What is polycondensation?
Monomers with functional groups react to form polymer.
What is polyaddition?
Two different monomers react to form a polymer
What are the three main categories of plastics?
- Thermoplastics
- Elastomers
- Thermosets
What are the three types of copolymers?
- Alternating copolymer
- Statistical copolymer
- Block copolymer
- Graft copolymer
What are the steps for the recycling of thermoplastics?
- Shredding
- Washing
- Drying
- Melting
What are some properties of thermosets? (7)
- Few plastics are thermosets
- Cross-linked polymer with 3-D network structure
- Covalent bonds linking the chains
- Stiff and brittle
- Temperature resistant
- Non-meltable
- Heat loosens bonds
What are the typical components of thermosets?
- Resin
- Curing Agent
- Accelerator
- Hardener
What are the production categories of plastics?(3)
- High-performance Plastics
- Technical Plastics
- Mass Plastics
What are some important plastics?
- Phenolic resin
- Epoxy resin
- Unsaturated polyester
resin - Polyimides
What are the three types of curing for plastics?
- Warm Curing
- Cold Curing
- Light Curing
Is curing endothermic or exothermic?
Exothermic
How do viscosity and temperature vary with time during curing?
Temperature increases then decreases
Viscosity decreases then increases
What is gel point?
Point after which resin can no longer be processed
What is degree of cure?
The percentage of resin that has cured.
What are the main characteristics of thermosets?(7)
- Undergo curing
- Low strain to failure
- Low fracture energy
- Irreversible processing
- Very low viscosity
- Absorb moisture
- Resistant to solvents
What are the advantages of thermosets? (6)
- Low processing temperature
- Good compression properties
- Resistant to creep
- Good fatigue properties
- Formable into complex shapes
- Highly resistant to solvents
What are the disadvantages of thermosets? (6)
- Long processing time
- Long cure
- Low ductility
- Low fracture toughness
- Low impact resistance
- Absorb moisture
What are some examples of epoxy resins?(3)
- Araldite
- UHU
- EPON
What are some properties of epoxy resins?
- Weather resistant
- Good insulating
properties - Low shrinkage
What are some examples of phenolic resins? (3)
- Bakelit
- Korex
- Vyntec
What are some properties of phenolic resins? (3)
- Very high stiffness compared to other polymers
- Low creep deformation
- Good fire properties
What are some properties of unsaturated polyester resins?
- High to very high stiffness and hardness
- Unresistant to permanent influence of hot water
- Yellow under sunlight, but weather resistant
What are some examples of polyamides? (3)
- Pl-film
- Pl-semi-finished product
- PMBI
What are some properties of polyamides? (4)
- High strength and stiffness
- Self extinguishing
- Used as both thermoplastics and thermosets
- Very good wear and sliding behavior
What are some basic properties of thermoplastics? (5)
- Absorb little moisture
- Limited resistance to
organic solvents - High strain to failure
- Reversible processing
- No curing required
What are the three classifications of thermoplastics?
- Standard Plastics
- Engineering Plastics
- High-performance
plastics
What does morphology mean?
Order/arrangement of a polymer structure.
What two morphologies exist in thermoplastics?
- Amorphous
- Semi-crystalline
What is the synthesis process for polyethene?
Radical or catalytic chain-growth polymerization.
What are the three types of polyethene?
- PE-HD
- PE-LD
- PE-LLD
What is polyethene resistant to? (5)
- Acids
- Bases
- Polar organic liquids
- Oils
- Fats
What is polyethene not resistant to? (3)
- Hydrocarbons
- Chlorinated
hydrocarbons - Oxidizing agents
How is PE-LD processed?
Extrusion
How is PE-HD processed?
Injection/Blow molding
How is poly propylene synthesised?
Catalytic chain-growth polymerization
How is polypropylene processed? (4)
- Injection Molding
- Extrusion
- Compression Molding
- Calendering
What is polypropylene not resistant to?
Strong oxidizing agents
How is PVC synthesised?
Radical polymerization of vinyl chloride in the liquid phase under pressure.
How is PVC differentiated by polymerization process? (3)
- PVC-E: Emulsion
- PVC-S: Suspension
- PVC-M: Mass
How is PVC differentiated by properties?(2)
PVC-U: Unplasticized, rigid
PVC-P: Plasticized, soft
How is PVC-U processed? (6)
- Extrusion
- Calendaring
- Injection Molding
- Blow Molding
- Sintering
- Compression Molding
What is PVC-U resistant to? (5)
- Acids
- Bases
- Aliphatic Hydrocarbons
- Oils
- Fats and Alcohols
What is PVC-U not resistant to? (3)
- Aromatic and Chlorinated hydrocarbons
- Ketones
- Esters
How is PVC-P processed?(6)
- Extrusion
- Calendaring
- Injection Molding
- Film Blowing
- Blow Molding
- Compression Molding
What is PVC-P resistant to? (3)
- Diluted acid/base
- Salt solutions
- Cleaning Agents
What is PVC-P not resistant to? (1)
All organic fluids
How is polystyrene synthesised?
Radical chain polymerization
What are the three types of polystyrene?
atactic, isotactic, and synotactic
How is polystyrene processed?
(Injection molding, extrusion, thermo forming, injection blow molding)
What is polystyrene resistant to? (5)
Bases, acids, alcohols, fats, oils
What is polystyrene not resistant to?
Hydrocarbons, halogen hydrocarbons, esters, ketones
How is polymethyl methacrylate synthesised?
Chain Polymerization
How is polymethyl methacrylate processed? (3)
- Extrusion
- Injection Molding
- Thermo forming
What is Polymethyl methacrylate resistant to? (2)
- Light acids and bases
- Non-polar solvents
What is Polymethyl methacrylate not resistant to? (1)
Polar solvents
How is polycarbonate synthesized?
Polycondensation
How is Polycarbonate processed?
- Injection molding
- Extrusion
- Blow molding
- Thermoforming
What is polycarbonate resistant to? (4)
- Diluted acids
- Fuel
- Oils
- Ethanol
What is polycarbonate not resistant to? (5)
- bases
- concentrated acids
- ketones
- esters
- aromatic and halogenated hydrocarbons
How is polyamide synthesized?
Polycondensation
How is polyamide processed?
Injection molding
What are some examples of nitrogenous thermoplastics? (3)
- Polyurethane
- Polyamide
- Polyacrylonitrile
How is polytetrafluoroethylene synthesized?
Chain polymerization
What is another name for polytetraflouroethylene?
Teflon
What is PAEK?
Polyaryletherketone
What is PEEK?
Polyether ether ketone
What are some processes for primary shaping of Plastics?(7)
- Extrusion
- Injection Molding
- Blow Molding
- Compression Molding
- Calendaring
- Spinning
- Casting
What are some methods used for forming of plastics? (1)
Thermo-forming
Why are thermoplastics used in aerospace? (7)
- Non-reacting
- Rapid processing
- High ductility
- High fracture toughness
- High impact resistance
- Absorb little moisture
- Can be recycled
What are some disadvantages of thermoplastics in aerospace? (4)
- High viscosity
- High processing
temperature - Poor creep resistance
- High processing pressure