3. Polymers

Question 1

what are the two ways of making polymers

Answer 1

addition polymerisation

condensation polymerisation

Question 2

what are polymers

Answer 2

long chain molecules formed when lots of small molecules named monomers join together

Question 3

how do alkenes form addition polymers

Answer 3

the double bonds open up and molecules join together to make long chains

Question 4

e.g. of addition polymerisation

n C2H4 ->

Answer 4

-(-C2H4-)- n
(n is the number of repeating units)
(the bit in the bracket is the repeating unit)

Question 5

1. what are condensation polymers usually formed from

2. how is the polymer chain created

Answer 5

1. two types of monomer
   each monomer has at least 2 functional groups
2. functional group of one monomer reacts with group on other type of monomer to form a link

Question 6

1. in condensation polymerisation each time a link is formed what is lost

Answer 6

1. a small molecule (usually water)

Question 7

2 examples of condensation polymers

Answer 7

polyesters

polyamides

Question 8

in polyesters what link is formed between the monomers

Answer 8

an ester link -COO-

Question 9

in polyamides what link is formed between the monomers

Answer 9

an amide link -CONH-

Question 10

condensation polymers are formed as what is removed

Answer 10

water

Question 11

how can condensation polymerisation be reversed

Answer 11

by hydrolysis (water molecules added back and links broken)

Question 12

why are condensation polymers hydrolysed with an acid or base

Answer 12

hydrolysis just with water is too slow

Question 13

polyamides hydrolyse more easily with an acid or a base?

Answer 13

with an acid

Question 14

1. polyesters hydrolyse more easily with an acid or a base?

2. what is formed

Answer 14

1. base

2. a metal salt of the carboxylic acid

Question 15

reactions between dicarboxylic acids and diamines make

Answer 15

polyamides

Question 16

Carboxyl -COOH groups react with amino -NH2 groups to form

Answer 16

Amide -CONH- links

Question 17

what is lost each time an amide link is formed

Answer 17

a water molecule (it is a condensation reaction)

Question 18

reactions between dicarbocylic acids and diols make

Answer 18

polyesters

Question 19

carboxyl groups -COOH react with hydroxyl groups -OH to form

Answer 19

ester links -COO-

Question 20

why does the fact that dicarboxylic acids and diamines have functional groups at each end mean long chains can form

Answer 20

both ends can react

Question 21

1.if one of the COOH in a dicarboxylic acid is changed to 2. an acyl chloride gorup it can also react to form
instead of water ____ is eliminated in the condensation reaction

Answer 21

1. polyesters and polyamides

2. hydrochloric acid is eliminated.