State the properties of thermoplastic polymers
Low stiffness
Low density
Stretchy
State the applications of polyethylene and polypropylene
Membranes
Sheeting
Pipes
Damp proof courses
What two things affect the properties of polymers
Crystallinity
Length
State the types of polyethylene
LDPE
HDPE
UHMWPE
State the two types of polyvinyl chloride
Plasticised
Unplasticised
State the properties of PVC
Resistant to weathering
Low maintenance
Durable
Thermally insulating
Not very UV resistant
State the applications of PVC
Sheets
Window frames
Pipes
State the applications of polycarbonate
Sheets for decorative or glazing purposes
Impact areas
Roofs
State the applications of polymethylmethacrylate
cases where you wouldn’t want to use glass
Sheets for decoration or glazing
Roofing tiles
Cladding
Adhesives and sealants
Coatings and paints
State the properties of polystyrene foams
Lightweight
Good insulation
Moisture resistant
State the applications of polystyrene
roof insulation
Wall insulation
Ceiling and attic insulation
Geotechnical insulation
Composite panels
State the properties of polyamides (nylon)
Resistant to damp vibration or grinding
Easy to form fibres
State the applications of polyamides
Geo textiles
Geo grids
Structural composites
State applications of bitumen
Paving
Roofing
State properties of thermosetting polymers
Stiff
Hard
Less stretchy
State applications of thermosetting polymers
Adhesives
Coatings
Laminates
Sports goods
Moulded components
Describe the formation of thermosets
Form a linear polymer - liquid
Curing and cross linking
Create bonds between chains
Accelerated by temp and pressure
state the stages of addition polymerisation
Initiation
Propagation
Termination
State potential additives in polymers
Stabilisers
Fillers
Plasticisers
Colourants
Flame retardants
State the advantages of stabilisers
Counteract polymer degradation
State the advantages of fillers
Improve compressive and tensile strength
Abrasion resistance
Toughness
Dimensional stability
Reduce polymer cost
State types of fillers
Wood flour
Silica flour
Sand
Glass
Clay
Talc
Limestone
What do plasticisers do?
Small molecules sit between large polymer chains
Increase inter chain distance
Reduce intermolecular bonding
Large additions can result in a liquid
