Polymers and fibres

Question 1

What are fibres made up of?

Answer 1

Polymers

Question 2

What are polymers?

Answer 2

-Large molecules
-Linked monomer units

Question 3

What are example of polymers?

Answer 3

-Vinyl chloride
-Styrene
-Glucose

Question 4

What is the process of joining polymers together?

Answer 4

Polymerisation

Question 5

What is a natural polymer?

Answer 5

Natural fibres
e.g. hemp or cotton, proteins, DNA

Question 6

What are semi-synthetic polymers

Answer 6

Part natural, part man-made
e.g. Rayon fibres and cellophane

Question 7

What are synthetic polymers?

Answer 7

Man-made
e.g. plastics: PVC, polystyrene, PTFE and nylon

Question 8

What are co-polymers?

Answer 8

-Very large molecules
-Different linker monomers
e.g. styrene and 1,3-butadiene

Question 9

What is a random co-polymer?

Answer 9

Monomer units organise themselves in a random fashion

Question 10

What are alternating co-polymers?

Answer 10

monomer units organise themselves in an alternating fashion

Question 11

What are block co-polymers?

Answer 11

Monomer units organise themselves into blocks

Question 12

What are graft co-polymers?

Answer 12

Long chain of a single monomer unit, with branches of other monomer units grafted on

Question 13

What are branched polymer chains?

Answer 13

Main chain with branches/side chains attached

Question 14

What is an example of a branched polymer chain?

Answer 14

Polyethylene, low density = high degree of branching

Question 15

What does a high degree of branching produce in polymer chains?

Answer 15

High flexibility

Question 16

What are flexible polymers used to produce?

Answer 16

Films

Question 17

What are non-flexible polymers used to produce?

Answer 17

Stiffer plastics used in bottles

Question 18

What is a cross linked polymer chain?

Answer 18

Linear chains which are joined together by small vertical chains at random positions along the main chain

Question 19

What is an example of a cross linked polymer chain?

Answer 19

-Poly(isoprene) rubber
-Epoxy resin (glue)

Question 20

What is a linear polymer chain?

Answer 20

Most common
Chains in a linear fashion

Question 21

What is an example of a linear polymer chain?

Answer 21

-PVC
-Polystyrene
-Nylon

Question 22

What is a dendrimer polymer chain?

Answer 22

Only used in specialised polymers, which have specific uses.
Every unit is branched

Question 23

What does chain growth polymerisation produce?

Answer 23

Makes plastics

Question 24

What does cationic polymerisation produce?

Answer 24

Bicycle tubes

Question 25

What does anionic polymerisation produce?

Answer 25

Superglue fuming for fingerprints

Question 26

What does step growth polymerisation produce?

Answer 26

Nylon

Question 27

What is step growth polymerisation further classified into?

Answer 27

-Thermoplastic -Thermosetting -Elastomers

Question 28

What is thermoplastic polymerisation?

Answer 28

-High glass temperature -Hard at room temp -Soft when heated e.g. Lego

Question 29

What is thermosetting polymerisation?

Answer 29

-Heated produces extensive 3D linkage -Highly cross linked -Solidifies and can't be reshaped or remoulded

Question 30

What does thermosetting polymerisation produce?

Answer 30

A hard, single, large molecule Inflexible and can crack e.g. Bakelite

Question 31

What is elastomer polymerisation?

Answer 31

-Ability to stretch and return to the original shape due to weak van der whal forces e.g. rubber, tires

Question 32

What are fibres?

Answer 32

-Thin threads of molten polymer extruded through a spinneret -Then cooled and drawn out along the axis of the fibre to give strength

Question 33

What are the classifications of natural fibres?

Answer 33

-Animal -Plant source -Mineral

Question 34

What is cellulose?

Answer 34

-A natural fibre -Large polymer unit made from glucose monomer units

Question 35

What are glucose units in cellulose held together by?

Answer 35

Hydrogen bonds

Question 36

What is a dicot fibre?

Answer 36

Has 2 seed leaves

Question 37

How does cellulose look under the microscope?

Answer 37

-Transparent -Colourless -Curved twisted fibres -Surface striations -Circular cross section

Question 38

What is kapok?

Answer 38

A seed fibre

Question 39

What do kapok fibres look like?

Answer 39

-Smooth -Hollow -Thin walled cylinders -Twisting and sharp bending -Silky like substance

Question 40

What are kapok fibres used for?

Answer 40

A stuffing agent Fibres are brittle and inelastic and can't be spun into fabric

Question 41

What are flax fibres?

Answer 41

-Dicot fibres -Skin fibres -High cellulose conc -Stronger than cotton

Question 42

What are hemp fibres?

Answer 42

-Dicot fibres -Comes from cannabis plant

Question 43

How do hemp fibres appear?

Answer 43

-Colourless -Transparent cylinders -Surface irregularities -Polygonal cross section

Question 44

What do synthetic fibres contain?

Answer 44

One polymer

Question 45

What are bicomponent fibres?

Answer 45

Contains 2 different polymers

Question 46

What are the general characteristics of bicomponent fibres?

Answer 46

-No surface characteristics -Regular and uniform shape -Can't be identified under microscope when comparing 2 fibres

Question 47

What is a nylon?

Answer 47

A step-growth polymer

Question 48

What does nylon consist of?

Answer 48

It's a molecule with an amine group on one end of the molecule and a carboxylic acid one another

Question 49

What is nylon used in?

Answer 49

Carpets Seatbelts

Question 50

What is kevlar?

Answer 50

The strongest synthetic fibre

Question 51

What does kevlar consist of?

Answer 51

monomer units are aramids, due to benzene ring Linked by hydrogen bonds

Question 52

What is kevlar used in?

Answer 52

Bulletproof vests Army uniforms

Question 53

What gives kevlar it's strength?

Answer 53

Network of hydrogen bonds

Question 54

What are semi-synthetic fibres?

Answer 54

Regenerated forms of cellulose

Question 55

What are rayon fibres?

Answer 55

Semi-synthetic fibres extracted from wood or cotton