Plastics

Question 1

What is the fundamental building block of plastics?

Answer 1

Carbon

Question 2

What are synthetic plastics made from?

Answer 2

Crude oil

Question 3

What is the single repeated unit that make up a plastic?

Answer 3

a monomer

Question 4

What process happens to monomers to transform them to polymers?

Answer 4

Polymerisation

Question 5

How are plastic properties altered?

Answer 5

Additives added to the polymers

Question 6

name some manufacturing processed used in the manufacture of plastics

Answer 6

extrusion
injection moulding
compression moulding

Question 7

What was the first synthetic plastic and when was it produced?

Answer 7

Bakelite in 1907

Question 8

What type of chemical bonding is prevalent in plastics?

Answer 8

covalent

Question 9

What must an organic molecule contain?

Answer 9

carbon

Question 10

What are the main types of hydrocarbons in crude oil?

Answer 10

Alkanes, Aromatics, cycloalkanes, alkenes, alkynes

Question 11

Give an example of an alkane

Answer 11

methane, ethane, propane, butane, isobutane, pentane, hexane

Question 12

Give an example of an aromatic

Answer 12

benzene, napthalene

Question 13

Give an example of a cycloalkane

Answer 13

Cyclohexane, methyl cyclopentane

Question 14

Give an example of alkene

Answer 14

ethylene, butene, isobutene

Question 15

Give an example of an alkyne

Answer 15

actylene, butadienes

Question 16

How are hydrocarbons refined?

Answer 16

fractional distillation

Question 17

What are the monomers for PTFE, PVC and PP?

Answer 17

PTFE : 2 flourine per carbon
PVC: 2 hydrogen on one carbon and a hydrogen and a cholrine on the other
PP: 2 hydrogen on one carbon and a hydrogen and a methyl group on the other

Question 18

What is the microstructure of a polymer like?

Answer 18

Can be chrystalline or amorphous
Have chrystalline and amorphous regions (semi chrystalline)
amount of chrystal phase changes properties

Question 19

What are the 2 different classes of polymers

Answer 19

Thermoplastics

Thermosetting plastics

Question 20

What are the properties of a thermoplastic?

Answer 20

Become soft and melt when heated
Can be moulded into a new shape that is retained on cooling
Can be reheated and remouled many times
Have plastic memory

Question 21

What are the properties of a thermosetting plastic?

Answer 21

• Set when first cooled down
• will not soften when reheated
• plastic will be destroyed before melted

Question 22

What allows the thermoplastics to be remoulded when heated?

Answer 22

They can be straight chain or branched chain, but they are held together by weak intermolecular bonding

Question 23

What are the effect of side chains on the properties of thermoplastics?

Answer 23

Side chains increase the distance between the main CC chain, this reduces the intermolecular attraction and results in different properties

Question 24

Give an example of how branches affect the properties of hydrocarbons

Answer 24

Low density polyethylene

High density poly ethylene (shorter branches)

Question 25

What makes a thermosetting plastic so strong?

Answer 25

They have networked covalent bonding and are cross linked with covalent bonding between chains

Question 26

Give an example of a thermosetting plastic

Answer 26

Bakelite, Phenolics, various epoxy resins and polyesters

Question 27

What is a polymer that is made form one or more polymer called?

Answer 27

A copolymer

Question 28

What are the different types of polymers?

Answer 28

Random Alternating Block Graft All of these give you different properties

Question 29

What are the general properties of polymers?

Answer 29

1. Combustible 2. Low melting point 3. Low solubility in water 4. High molecular 5. Variable molecule size 6. Low compressive strength 7. Low stiffness 8. High toughness 9. Low density 10. Durable 11. Softens at low temperatures 12. Low thermal conductivity 13. Electrical insulators 14. Low permeability 15. Flexible 16. Available in many forms

Question 30

How much plastic is produced per year worldwide?

Answer 30

~300 million tonnes

Question 31

How much is plastic consumption growing by in europe?

Answer 31

4% per year

Question 32

How much of the plastic produced per year is used in construction, and how much in packaging?

Answer 32

1/3 in packaging, 1/4 in construction

Question 33

What are some examples of high volume plastics?

Answer 33

Polyethylene (PE): containers , pipes, bags... Polyvinylchloride (PVC): windowframes, pipes, flooring Polypropylene (pp): film, chairs, fibres, car bumpers Polystyrene (PS): packaging, thermal insulation, cups Polyethylene tetrephthalate (PET): bottles, film, food packaging Polyurethane (PU): adhesives, trainer soles, furniture foam Acrylonitrile butadiene styrene (ABS): transparent all-weather sheet, electrical insulators

Question 34

What % of plastics are used in the construction sector?

Answer 34

23%

Question 35

Describe the process behind injection moulding?

Answer 35

Ram pushes plastic into a screw in a barrallel, where plastic granules are fed across heaters through a nozzle. Molten plastic is fed into a mold, where it is then ejected and the part is formed

Question 36

What are the signature features of injection moulding?

Answer 36

An injection and ejection points

Question 37

What is the process behng compression molding?

Answer 37

Thermoset or thermoplastic charge is placed in mold | The mold has a plunger at the bottom which ejects it after molding

Question 38

How is plastic used in construction?

Answer 38

Plastics in construction are used for pipes and ducts. Nearly 30% are for insulation products, and the rest are for windows and floor coverings

Question 39

What plastic is used in landfills?

Answer 39

HDPE, it is used as a landfill liner | LDPE is used as a landfill cover

Question 40

What is the main plastic used in construction?

Answer 40

PVC

Question 41

What is bitumen produced from?

Answer 41

Crude oil during fractional distillation It is the heaviest fraction with the highest boiling point >370C Can also be found in natural deposits

Question 42

What kind of plastic is bitumen?

Answer 42

Thermoplastic

Question 43

What benefitial properties does bitumen have?

Answer 43

Waterproofing and adhesive

Question 44

What are the main chemical groups in bitumen

Answer 44

Asphaltenes and maltenes exact composition depends on the crude oil and distiallation process

Question 45

What are the three different types of maltenes?

Answer 45

resins, aromatics and saturates

Question 46

Why is bitumen such a good binder for asphalt?

Answer 46

Bitumen can either actaas a straight forward binder, or its properties can be used depending on the ratio of aggregates to bitumen