1.2 - Performance Characteristics Of Materials Flashcards
(85 cards)
1
Q
Reasons for manufacturers making use of bio polymers and biodegradable polymers ?
A
- increased environmental awareness
- technological advancements
2
Q
What are products that can be made from bio/degradable polymers?
A
- cutlery / food trays / bags / plant pots / disposable gloves and nappies
- disposing stitches
3
Q
What are the two categories that bio-polymers ?
A
- natural and synthetic
4
Q
What are natural bio-polymers ?
A
Polymers made from natural materials such as cellulose, starch and polysaccharides
5
Q
What is a synthetic bio-polymer ?
A
Polymers made from renewable sources but chemically engineered to break down more quickly
6
Q
Example of a synthetic bio-polymer ?
A
Corn kernels - milled to extract dextrose from their starch - dextrose is fermented to produce lactic acid - processed to produce pla
7
Q
What are the factors that allow polymer degradation to occur ?
A
- light
- heat
- chemical
8
Q
What do you call a plastic that can degrade due to the presence of light ?
A
Photodegradable
9
Q
What do you call a plastic that can degrade due to the presence of water ?
A
Hydro-degradable
10
Q
What do you call a plastic that can degrade due to the presence of oxygen ?
A
Oxy degradable
11
Q
How does degradation of polymers occur ?
A
Action of microorganisms , which convert the polymer into water , co2 , biomass and possibly methane
12
Q
Describe the use of oxy degradable polymers
A
13
Q
Describe how oxydegradable polymers degrade
A
The polymer breaks down into fine powder due to exposure to oxygen
- time taken to degrade can be programmed during manufacture ( few months to years )
14
Q
Example of using oxy degradable polymers ?
A
- ldpe bags
Which break down into small confetti shapes then into a powder
15
Q
Describe how photodegradable polymers degrade ?
A
Polymer bonds are weakened and the polymer breaks down during to uv light exposure
16
Q
Use of photodegradable polymers ?
A
- agriculture industry , to cover the ground acting as a mulch to prevent weed growth when growing crops - decreasing the need for herbicides
17
Q
Describe how hydro- degradable polymers degrade ?
A
The polymer breaks down due to exposure with h20
18
Q
Uses of hydro degradable polymers ?
A
Liquid detergent sachets - watching machines and dishwashers
19
Q
When will hydro degradable polymers be useful ?
A
In preventing cross contamination.
- chemical plants and hospitals
20
Q
Implications of using bio degradable polymers ?
A
- degradable polymers produce methane gas when they decompose
- degradable polymers may require higher temperatures and may leave toxic residue
- can’t be recycled encouraging to the throw away culture
21
Q
Implications of using bio- polymers ?
A
- natural bio polymers require land to grow the crops resulting in traditional agricultural land being converted to grow polymers
- increase in food costs
- may be genetically modified to produce plants with desired qualities - may be seen to be moral
22
Q
What is the source of corn starch polymer ?
A
- high starch vegetables such as corn , potatoes and maize
23
Q
Uses of corn starch polymer?
A
- packaging
- straws
- takeaway food containers
- bags
- cutlery
24
Q
What is the source of potatopak ?
A
- potato starch
25
What are the uses of potatopak ?
- single use items such as bowls , cutlery and food trays
- packaging beads or peanuts
26
What is the trade name for polyhydrocybutyrate ( PHB ) ?
Bio pol
27
What is the source of biopol
Made from bacteria grown in cultures- promote degradation in polymers ( 1% )
28
Uses of pla ?
- filament for 3d printing
- single use bottles
- carrier bags
- plant pots
29
What are uses of bio pol ?
- packaging
- Carrier bags
- plant pots
- single use bags
- surgical stitches
- pill covers
30
What is the source of poly lactic acid ?
- corn kernels or sugar canes , fermented to produce lactic acid - synthesised to produce pla
31
What is the source of polyhydroxyalkonate ( pha ) ?
- made from bacteria grown in cultures
32
Uses of polyhydroxyalconate?
- screws and bone plates
- slow release medication patches
- films
33
What is the source of lactide ?
Pla and cellulose based
34
Uses of lactide ?
- biomedical applications
- bone repair fixings
- slow release medication patches
- films
35
What is the source of glycolide ?
- pla and cellulose
36
Uses of glycolide ?
- Food film
- bags
- packaging wraps
- bin bags
37
What does the ability of the polymer to degrade depend on ?
- the structure of the polymer
38
What are composites ?
A material comprised of two or more different materials resulting in a material with enhanced properties
39
Name 4 Properties of carbon fibre reinforced polymers .
- lightweight
- corrosion resistant
- tough
- low thermal expansion
- hard
- good compressive strength
40
Uses of carbon fibre reinforced plastic ?
- sports equipment
- racing car bodies
- helmets
- prosthetics
- bike frames
-
41
What is carbon fibre reinforced plastic made from ?
- carbon fibres mixed with polyester resin
42
What is GRP made from ?
Glass fibres mixed with polyester resin
43
What are 4 properties of GRP ?
- lightweight
- corrosion resistant
- tough
- hard
- low thermal expansion
- compressive strength
44
Name 3 Uses of GRP
- Boat hulls
- kayak shells
- pond liners
- sports car bodies and parts
45
What is the composition of tungsten carbide ?
- a cement ( ceramic and metal particles )
Ceramic tungsten and cobalt metals
46
What are 4 properties of tungsten carbide ?
- hard
- tough
- resistant to high temp
- corrosion resistance
47
Uses of tungsten carbide ?
- cutting tools such as drill bits , lathe tool tips , router bits , kitchen knives
48
What is aluminium composite boards ?
Aluminium sheets with a polyethylene core
49
4 Properties of aluminium composite board ?
- lightweight
- tough
- malleable
- good thermal and sound insulation
- good vibration dampening
50
Uses of aluminium composite board ?
- sound proofing panels in cars
- buildings and boats
- signage
51
What is concrete ?
Cement powder , sand , aggregate particles mixed with water
52
Properties of concrete?
High compressive strength , few surface deflects , easy to mould , low tensile strength
53
Uses of concrete ?
- pathways
- beams
- driveways
- house foundations
54
What is reinforced concrete ?
Concrete with Low carbon steel rods ( rebar )
55
What are properties of reinforced concrete ?
- Fire resistant
- high compression an tensile strength
- consistency across the structure
- few surface defects
56
Uses of reinforced concrete?
- buildings
- bridge piles and spans
- grid floors
57
What is fibre cement ?
Cement poser , sand , aggregate particles and polymer of steel fibres mixed with water
58
Properties of fibre cement ?
- Lighter in weight that reinforced concrete
- hard
- tough
- good at low temperatures ( freeze thaw situations )
59
Uses of fibre cement ?
- suspended floors and pathways
60
What is engineered wood ?
Timber laminates and mf adhesive
61
Properties of engineered woods ?
- good aesthetics
- natural alternatives to concretes
- fire resistant
- good structural stability
62
Uses of engineered woods ?
- beams
- bridges
- domes
- arches
- decking
63
What are smart materials ?
Materials that change their physical properties due to an input or change in environment ( external stimulus)
64
How does shape memory alloys work ( nitinol ) ?
Changes shape in response to change in temperature ( transitional temperature at 70 degrees ) or electrical input
65
What are uses of shame memory alloys ?
- dental braces
- self closing windows
- bio engineering stents
- bone plates
66
How do thermochromic pigments work ?
Changes colour in response to temperature change
67
Uses of thermochromic pigments
Room thermometers , medical thermometers, colour change mugs and kettles , baby feeding spoons
68
What are phosphorescent pigments ?
Pigments that absorb light energy ( uv ) during the day and re- emits the light energy when dark as visible light
69
Uses of phosphorescent pigments ?
Fire exits , adhesives stars , smiskis
70
How do photochromic pigments work ?
Pigments that change colour with the intensity of light
71
Uses of photo chromic pigments?
Welding goggles , security markers that show under uv light , reactive spectacles
72
What is electroluminescent wire ?
Thin copper wire coated in phosphorescent material which glows in response an alternating current
73
Uses of electroluminescent wire ?
Glow bracelet, home decorations
74
What is a piezoelectric material ?
Gives off a small electrical charge when deformed - increases in size ( 4 percent ) when an electrical current is passed through it
75
What are uses of piezoelectric materials ?
Airbag sensors , lighters for barbecues , vibration damping in tenses racquets , musical greeting cards
76
What are modern materials ?
Materials that have developed due through he invention of improved processes
77
What are features of Kevlar ?
High cut and heat resistant features
78
Uses of Kevlar ?
Body armour , cut- proof gloves and aprons , aerospace applications, puncture resistant bike tyres
79
What is PMC ?
- a clay consistency material made of fine metal particles. Works like ceramic clay , easily mouldable , easy to shape and form , sets hard once fired with a kiln or butane torch
80
What are features of pmc ?
Inexpensive in comparison to solid metals such as silver
81
Uses of pmc ?
- sculptures
- jewellery
- decorative items
82
What are features of high density modelling foam ?
- light weight
- easy to work with using traditional wood working tools ( cnc milling / routers )
- sands easily to allow intricate shapes and forms to be created
83
What are uses of high density modelling foam ?
- 3d modelling, prototypes
84
What are features of polymorph ?
Mouldable at 60 degrees ( heated in water or with a hair dryer )
Solidifies at room temp
85
Uses of polymorph ?
- shaping ergonomic handles
- modelling ns
- prototype mechanical parts
