29 - Polymerisation Flashcards
What are condensation reactions?
When two molecules react together and a small molecule (often H2O or HCl) is eliminated.
What are condensation polymers?
Polymers made from two different monomers, each of which has two functional groups. Both functional groups can react, forming long-chain polymers.
What is addition polymerisation?
When all the atoms in the monomer is used to form the polymer.
What is the ester link?
COO–
What is the amide link?
OC-NH
What are polyesters?
Polymers that have the ester linkage repeated over and over again.
What functional groups are used to make polyesters and what is eliminated?
Diols + dicarboxylic acids
H2O eliminated
What are the uses of polyesters?
Packaging and internal stiches.
Why are polyesters and polyamides biodegradable?
Ester and amide linkages are susceptible to hydrolysis.
And photo biodegradable as the C=O bond absorbs radiation.
What are polyamides?
Polymers that have the amide linkage repeated over and over again.
How are polyamides made?
diaminoalkanes (two amine groups on an alkane chain) + dicarboxylic acids.
What are the reagents for Nylon 6,6?
HOOC-(CH2)4 - COOH + H2N - (CH2)6 - NH2
What is the mechanism for the formation of nylon 6,6?
Addition-elimination.
What links are formed in nylon 6,6?
Amide links.
What are the reagents for Kevlar?
benzene-1,4-diamine + benzene-1,4-dicarboxylic acid.
What links are formed in kevlar?
amide links
Why are poly(alkenes) non-boidegradable?
They are unreactive dues to their strong non-polar CH and CC bonds.
Why is kevlar so strong?
Due to the rigid chains and the ability if the flat aromatic rings to pack together, held by strong intermolecular forces.
How can you speed up boidegration?
Change the conditions to acidic or alkaline.
Why are polypeptides considered polyamides?
The amine group of one amino acid reacts with the carboxylic acid group of another and a molecule of water is eliminated, and a condensation polymer is formed.
