Polyester And Polyamides

Question 1

Define condensation polymerisation

Answer 1

When a water molecule is removed from the species of a reaction. Polyesters and polyamides can be formed this way.

Question 2

How are polyesters formed?
Draw a displayed formula equation

Answer 2

When a dicarboxylic acid and a diol react together, producing an ester linkage, -COO-.

HOOC-R-COOH + HO-R-OH = -HOOC-R-COO-R-O-
Don’t forget square brackets

Question 3

Why are polyesters useful?

Answer 3

Because they can be broken down through hydrolysis due to the polarity within the polymer molecules. therefore, they are biodegradable and can be broken down easily in nature by naturally occurring water or moisture.
This means that they will eventually break down.

Question 4

What are polyamides?
Draw displayed formula equation

Answer 4

Condensation polymers generally formed in a reaction between a dicarboxylic acid and a diamine. A molecules of water is removed. Producing an amide linkage.

HOOC-R-COOH + H2N-R-NH2 = -OOC-R-CONH-R-NH-

Don’t forget about the square brackets

Question 5

Define addition polymerisation

Answer 5

The formation of a long chain molecule when many monomers join together.

Question 6

What is ester hydrolysis?

Answer 6

reverse reaction to esterification. Esters can either be hydrolysed with hot aqueous acid or hit hot aqueous alkali.

Question 7

When an ester or polyester undergo hydrolysis in acidic conditions, what are the reagents and products?

Answer 7

water in acidic conditions (hot aqueous acid) added to ester/polyester
For ester - Carboxylic acids and alcohol. Reverse of esterification
For polyester - a diol and carboxylate salt would form

Question 8

When an ester and polyester undergo hydrolysis in basic conditions, what are the reagents and products?

Answer 8

Hot aqueous alkali (NaOH)
Ester - carboxylate salt and alcohol
Carboxylate salt is formed as it reacts further with the base to form a salt.

Question 9

What is amide hydrolysis?

Answer 9

Amides can be hydrolysed under acidic coonditions or under alkaline conditions. Polyamides can be hydrolysed in a similar way.

Question 10

When an amide is hydrolysed under acidic conditions what are the products?

Answer 10

carboxylic acid and ammonium salts.

Question 11

When an amide is hydrolysed under alkaline conditions what are the products?

Answer 11

Carboxylate salts and either ammonia or amine.

Question 12

When polyamides are hydrolysed what forms?

Answer 12

Converts polyamide back into the diamine and dicarboxylic acids.