8 - Performance characteristics of Polymers Flashcards
Define thermosetting polymer (2)
- A material which when heated undergoes a chemical change whereby the molecules from rigid cross links
- They cannot be reheated and reshaped, even at very high temperatures
Names of thermosetting polymers (4)
- Urea Formaldehyde (UF)
- Melamine formaldehyde (MF)
- Polyester resin
- Epoxy resin
Properties of Urea formaldehyde (5)
- Hard
- Heat resistant
- Good electrical insulator
- Brittle
- Safe working temp 80°c
Uses of urea formaldehyde (2)
- Electrical fittings
- Adhesives
Properties of melamine formaldehyde (MF) (6)
- Hard
- Opaque
- Tough
- Heat resistant food safe
- Chemical resistant
- Safe working temp 130°c
Uses of melamine formaldehyde (MF) (3)
- Decorative laminates
- Picnic ware
- Buttons
Properties of polyester resin (5)
- Rigid • Heat resistant
- Chemical resistant
- Brittle
- Safe working temp 95°c
Uses of polyester resin (3)
- Castings
- Used in layup process for glass reinforced plastic (GRP) for boat hulls
- car parts e,g chair seats
Properties of epoxy resin (6)
- Rigid
- Clear
- Hard
- Tough
- Chemical resistant
- Safe working temp 80°c-200°c
Uses of epoxy resin (6)
- Adhesives
- Surface coatings
- Encapsulation of electrical components
- Cardiac pacemakers
- Aerospace applications
- Used in lay-up techniques with Carbon fibre reinforced plastic
Define a thermoforming/thermo plastic
A material that can be repeatedly reheated and shaped
Names of thermoplastics (9)
- Low density polyethylene (LDPE)
- High density polyethylene (HDPE)
- Polypropylene (PP)
- High impact polystyrene (HIPS)
- Acrylonitrile butadiene (ABS)
- Polymethylmethacrylate (PMMA)
- Nylon
- Rigid polyvinyl chloride (uPVC)
- Flexible polyvinyl chloride (PVC)
Properties of low density polyethylene (LDPE) (6)
- Very tough
- Good chemical resistance
- Weatherproof
- Available in translucent
- Low level of rigidity
- Safe working temp 65°c
Uses of low density polyethylene (LDPE) (5)
- Squeezy detergent bottles
- Toys
- Carrier bags
- Bin liners
- General packaging - food wrap film, food trays
Properties of high density polyethylene (HDPE) (5)
- Available in translucent form
- Weatherproof
- Tough
- Good chemical resistance
- Safe working temp 65°c
Uses of high density polyethylene (HDPE) (7)
- Chemical drums
- Jerry cans
- Toys
- Household and kitchen ware
- Long life Carrier bags
- Buckets
- Bowls
Properties of polypropylene (PP) (3)
- Available in translucent form
- Good chemical resistance
- Safe working temp 65°C
Uses of polypropylene (PP) (6)
- Rope
- Folders
- Folio cases
- food containers
- Medical equipment
- Hinged container lids
Properties of high impact polystyrene (HIPS) (5)
- Hard
- Rigid
- Available in translucent form
- Tough
- Safe working temp 70°c
Uses of high impact polystyrene (HIPS) (4)
- Yoghurt pots
- Refrigeration linings
- Single use drink cups
- Instrument control knobs
Properties of Acrylonitrile butadiene styrene (ABS) (4)
- Extremely Tough
- Hard
- Available in opaque
- Safe working temperature 80°c
Uses of Acrylonitrile butadiene styrene (ABS) (7)
- Telephone handsets
- Rigid luggage
- Domestic appliances
- Handles
- Computers
- Remote control casings
- Calculator casings
Properties of polymethylmethacrylate (PMMA) (5)
- Tough
- Hard
- Good chemical resistance
- Available in translucent
- Safe working temp 95°c
Uses of polymethylmethacrylate (PMMA) (5)
- Car light casings
- CNC laser cut items
- Lighting units
- Lighting covers
- Baths
Properties of nylon (5)
- Tough
- Corrosion resistant
- Good temperature resistance
- Low co-efficient of friction
- Safe working temp 150°C
Uses of Nylon (7)
- Bearings
- Gears
- Curtain rails
- Textiles
- Boil-in-the-bag food packaging
- Car engine manifolds
- Cable ties
Properties of Rigid polyvinyl chloride (uPVC) (7)
- Rigid
- Opaque
- Tough
- Hard
- Good weathering resistance
- Fire retardant
- Safe working temp 95°C
Uses of Rigid polyvinyl chloride (uPVC) (5)
• Window frames • External doors • Guttering and downpipes for buildings • Water service pipes • Bank cards
Properties of flexible polyvinyl chloride (PVC) (6)
- Available in translucent
- Tough
- Flexible
- Good weathering resistance
- Good chemical resistance
- Safe working temp 95°C
Uses of Flexible polyvinyl chloride (PVC)(5)
- Hose pipes
- Cable insulation
- Medical grade tubing
- Inflatable products
- Imitation leather seat coverings
What are elastomers?
Are materials that ,at room temperature, can be deformed under pressure and then, upon release of the pressure, will it return to its original shape
Examples of elastomers (3)
- Natural rubber (polyisoprene)
- Butadiene rubber (BR)
- Neoprene (polychloropone rubber)
Properties of natural rubber (polyisoprene) (5)
- High tensile strength
- Low elongation
- Good hardness (compared to others)
- Electrical insulator
- Good cold resistance
Uses of natural rubber (polyisoprene) (8)
- Automotive industry e.g tyres
- Tubes
- Hoses
- Gaskets
- Belts
- Balloons
- Toys
- Footwear
Properties of butadiene rubber (BR) (4)
- Tough
- Excellent wear resistance against friction
- Good thermal resistance against friction
- Electrical insulator
Uses of butadiene rubber (BR) (6)
- Vehicle tyres
- Shoes soles
- Toys
- Conveyor belts
- Water
- Pneumatic hoses
Properties of Neoprene (polychloroprene rubber) (6)
- Good thermal resistance
- Toughness
- Good oil and chemical resistance
- Excellent weather resistance
- Good abrasion resistance
- Electrical insulator
Uses of Neoprene (polychlroprene rubber) (8)
- Wetsuits
- Laptop cases
- Industrial wire insulation
- Automatice applications e.g shock absorber seals
- Hose covers
- Transmission belts
- Gaskets
- Door seals
Properties of silicone (6)
- Good flexibility at low temperatures
- Poor abrasion resistance
- Good thermal resistance and resistance to temperature extremes
- Good weather resistance
- Good lubricating qualities
- Electrical insulator
Uses of silicone (8)
- Flexible ice cube trays
- Bakeware
- Cooking utensils
- Seals for refrigerators
- Machinery lubricant
- Sealants
- Mould making
- Medical uses e.g lubricants for prosthetics, tubing for drug delivery systems
Plastics recycling
Why are polymers enhanced?
To offer several advantages such as improved aesthetics and working properties through additives
Performance characteristics of polymers (12)
- Toughness
- Biodegradeability
- UV resistance
- Corrosion resistance
- Chemical resistance
- Liquids resistance
- Self finishing
- Melting points
- Recyclability
- Elasticity
- Ability to be moulded
- Suitability for food packaging applications
Characteristics of polymers
- Made mostly from a non-renewable energy resource in crude oil
- Synthetic polymers are made from crude oil and take hundreds of years to degrade
- Polymers are self finished as it can be pigmented during the manufacture process to give colour therefore require no secondary finishing process
Stock forms (6)
- Granules - a small particle of plastic
- Sheet - large flat sections of polymer in varying thicknesses
- Film - very thin sheet polymer
- Rods and other extruded forms, tubes and bars
- Foam - solid form made by including air or other gases e.g styrofoam from expanded polystyrene
- Powder - a very fine granule of polymer
