4.2d Plastics Flashcards
What are the raw materials for plastics?
Derived from petro-chemicals (crude oil, coal, natural gas)
Plastics are polymers in which the different types of bonds determine the physical/ mechanical properties
What is the molecular structure of thermoplastics?
Linear chain molecules
Weak secondary bonds between chains
ductile
low stiffness
easily injected into a mold
reshaped after heating
low production cost
What is the molecular structure of thermosetting plastics and its properties?
Linear chain molecules
Strong primary bonds between adjacent polymer chains
high stiffness
high strength
can not be reheated / remolded
heat resistant
What are the types of thermoplastics?
PP (Polypropylene)
PE (Polyethylene)
HIPS (High Impact Polystyrene)
ABS
PET (Polyethylene terephthalate)
PVC (Polyvinyl Chloride)
What are the properties of PP (Polypropylene)?
High temperature resistance
What are the properties of PE (Polyethylene)?
Flexible
What are the properties of HIPS (High Impact Polystyrene)?
Easy to shape
What are the properties of ABS?
Heat resistance
What are the properties of PET (Polyethylene terephthalate)?
Impact resistant
What are the properties of PVC (Polyvinyl Chloride)?
High hardness
What are the types of thermoset plastics?
Polyurethane
Urea-formaldehyde
Melamine resin
Epoxy resin
What are the properties of Polyurethane?
Good insulator, and high tensile/compressive strength
What are the properties of Urea-formaldehyde?
High tensile strength
What are the properties of melamine resin?
High electrical resistance
What are the properties of epoxy resin?
High mechanical strength (tensile/compressive)