NCEA Level 3 | Chemistry | Organics | Polymers and Hydrolysis

polymers

large molecules composed of small repeating units called monomers

condensation polymer

a polymer formed by condensation reactions, involving the release of a small inorganic molecule

ester linkage

remove the OH from -COOH (or the Cl from -COCl) and the H from -OH, then the carbonyl carbon bonds to the remaining O

polyester

condensation polymer in which the monomers are joined through ester linkages

What two ways are there of forming polyesters (via condensation polymerisation)?

1. a dicarboxylic acid or a diacyl chloride + a diol (all have a functional group on either end)

2. a single monomer with a carboxylic acid or acyl chloride on one end and a hydroxyl group on the other

amide linkage

remove the OH from -COOH (or the Cl from -COCl) and an H from -NH2, then the carbonyl carbon bonds to the N

polyamide

condensation polymer in which the monomers are joined through amide linkages

What two ways are there of forming polyamides (via condensation polymerisation)?

1. a diacyl chloride + a diamine (all have a functional group on either end)

2. a single monomer with an acyl chloride on one end and an amine group on the other

amino acids

monomers of proteins

What do amino acids contain?

an amino group, a carboxyl group, and a unique side chain bonded to a central C

How do amino acids bond?

peptide bonds - an amide linkage, releasing H2O

hydrolysis

reaction where large molecules are broken down into smaller ones after the addition of water

acid hydrolysis

the water used in hydrolysis is acidified, so any functional groups that can will be protonated (e.g., amine, hydroxyl group)

protonate

transfer a proton (H+) to a molecule

deprotonate

remove a proton (H+) from a molecule

base hydrolysis

the water used in hydrolysis is alkaline, so any functional groups that can will be deprotonated (e.g., amine, hydroxyl group)

triglycerides

energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid, joined via an esterification reaction

glycerol

propan-1,2,3-triol

fatty acids

carboxylic acids with long hydrocarbon chains

acid hydrolysis of triglycerides

forms a glycerol and 3 carboxylic acids

base hydrolysis of triglycerides

forms a glycerol and 3 carboxylate ions (no H+ available)

if a base like NaOH is added, the ion will form a carboxylate salt

acid hydrolysis of esters

forms a carboxylic acid and an alcohol

base hydrolysis of esters

forms a carboxylate ion and an alcohol

acid hydrolysis of amides

forms a carboxylic acid and an ammonium salt (contains an ammonium cation)

base hydrolysis of amides

forms a carboxylate ion and an amine

if a base like NaOH is added, the ion will form a carboxylate salt

What is needed for the hydrolysis of esters and amides?

an acidic/basic catalyst, and heat under reflux