CHEMISTRY MODULE 7 AND 8
COMPREHENSIVE EXAM 2026
◉ carbon-carbon bond formation. Answer: how chain-growth
polymers generally grow
◉ Polyamide (Nylon). Answer: formed by combining 1,6-
diaminohexane (amine) with 1,6-hexandioic acid (carboxylic acid)
amine functionality reacts with carboxylic acid functionality to form
an amide with a corresponding loss of a water molecule
◉ cellulose, polypetide chains, beta-Hydroxybutyric acid. Answer:
naturally occurring step-growth/ condensation polymer examples
◉ Lexan. Answer: step-growth
polymer: polycarbonate
eye glasses, auto parts, drinking glasses
◉ Kevlar. Answer: step-growth
polymer: polyamide
body armor, tires, helmets
,◉ Dacron, Mylar. Answer: step-growth
polymer: polyester
eletric/thermal insulation, helium balloons, artificial limbs
◉ 1. free radical
2. cationic
3. anionic. Answer: three main mechanisms for addition/ chain-
growth polymerization
◉ begins by creating a reactive intermediate that starts the chain
reaction. Answer: For all three main addition mechanisms, how does
polymerization begin?
◉ free-radical addition polymerization. Answer: a monomer reacts
with a free-radical initiator to create a free-radical
◉ free-radical. Answer: an atom or a group of atoms that has one
unpaired electron
◉ radical initiator. Answer: a reagent that creates radicals, has
relatively weak covalent bonds which can be homolyzed
, ◉ 1. electrically neutral
2. quite reactive and reacts quickly to pair up the lone electron
3. formed from radical initiators. Answer: 3 main characteristics of
free-radicals
◉ Homolyzed. Answer: broken so that each atom joined by the bond
gets one of the two electrons in the bond
◉ benzoyl peroxide. Answer: example of a radical initiator (o-o bond
= weak and can undergo homolysis upon heat or UV exposure to
produce 2 benzoyl radicals)
◉ only a small amount of radical initiator is needed compared to the
concentration of monomers present
-some remains in final product but it does not affect the product.
Answer: how much initiator is needed in polymerization and does
any remain at the end of the reactions?
◉ 1. the monomer used
2. the molecular weight of the final polymer chain. Answer: two
main things that control polymer properties