Polyesters & Polyamides Flashcards
What is condensation polymerisation?
The joining of monomer to form a long chain of monomers, known as a polymer, with the loss of a small molecule - usually H2O or HCl - 2 different functional groups are required
What is a polyester?
A condensation polymer formed when monomers are joined by ester linkages in a long chain
What can polyesters be made from?
- 1 monomer containing both a carboxylic acid and alcohol group
- 2 monomers, one containing 2 carboxylic acid groups and the other containing 2 alcohol groups
How can a polyester be made from 1 monomer containing 2 functional groups?
Lining up the monomers: the -OH is lost off the carboxylic acid group and the -H is lost off the alcohol group.
H2O is taken and an ester group/linkage is made between the the C=O and the -O
What is formed when making a polyester?
The polyester (ester linkage) and water
What monomers do you need to form a polyester from 2 different monomers?
- A diol ( 2 alcohol groups)
- A dicarboxylic acid ( 2 carboxyl groups)
How can a polyester be made from 2 monomers each containing 2 functional groups?
Lining up the varying monomers: -OH is taken off the dicarboxylic acid and -H is taken off the diol
Ester linkage forms from the C=O on the dicarboxylic acid and the -O left on the diol
How many waters are made when making a polyester from 2 different monomers?
2n - 1
where n is the number of monomers for one of the monomers (n is the same for both monomers)
What is a polyamide?
A condensation polymer formed when monomers are joined by amide linkages in a long chain
What can polyamides be formed from?
- 1 monomer containing both a carboxylic acid (or acyl chloride) and an amine group
- 2 monomers, one containing 2 carboxylic acid (or acyl chloride) groups and the other containing 2 amine groups
What contains both an amine groups and a carboxyl group?
Amino acid
What forms when amino acids undergo condensation polymerisation?
Polypeptides or proteins
How can a polyamide be made from 1 monomer containing 2 functional groups?
Lining the monomers up: -OH is lost off the carboxyl group and -H is lost off the amine group.
An amide linkage is formed from the C=O in the left carboxyl and the -NH in the left amine group. H2O is formed as well.
What monomers do you need to form a polyamide from 2 different monomers?
- A diamine ( 2 amine groups)
- A dicarboxylic acid ( 2 carboxyl groups) (or an acyl chloride)
How can a polyamide be made from 2 different monomers?
Lining the monomers up: -OH is lost off the dicarboxylic acid and -H is lost off the diamine group
An amide linkage is formed from the C=O left from the carboxyl and the -NH left from the diamine. (2n-1) H2O is also formed
What can polyesters & polyamides be hydrolysed by?
Hot aqueous alkali (eg NaOH) or hot aqueous acid (eg HCl)
What are the reagents of base hydrolysis?
NaOH & H2O
What are the reagents of acid hydrolysis?
H+ & H2O
What is formed from the base hydrolysis of a polyester?
A carboxylate salt with Na and a diol
What is formed from the acid hydrolysis of a polyester?
A carboxylic acid and an alcohol
BASE HYDROLYSIS
NaOH/ H2O
ACID HYDROLYSIS
H+ / H2O
What is formed from the base hydrolysis of a polyamide?
A carboxylate salt with Na and a diamine
What is formed from the acid hydrolysis of a polyamide?
N+H3 chains off the main body where the diamine groups were and a carboxylic acid
BASE HYDROLYSIS
NaOH/ H2O
ACID HYDROLYSIS
H+ / H2O
Why is the ability for polyesters and polyamides to be hydrolysed a major advantage - specifically over polyalkenes?
This makes them biodegradable - when taken to a landfill they break down easily
What are the characteristics of addition polymerisation?
- Monomer contains a C=C bond
- The backbone/main section of the polymer is a continuous chain of carbon atoms
What are the characteristics of condensation polymeristaion?
- 2 monomers, each with 2 (of the the same) functional groups OR
- 1 monomer with 2 different functional groups
- Polymer contains ester or amide linkage
