Video Transcript
Chemists use A- and B-type monomers
to make different types of synthetic polymers. Which of the following synthesized
substances cannot be classified as a copolymer material? (A), (B), (C), (D), (E).
Polymers are chemicals that are
formed from similar chemical units, otherwise known as monomers, that join
together. Many polymers assemble from a large
number of monomers. In the example shown, the letter 𝑛
represents a generally large number. And the yellow circles represent a
single monomer unit. The structure from the reaction of
monomers is generally easy to predict, because the polymer is made up of repeating
monomer units. For example, polymers like the
polyethene macromolecule are made from ethene monomers.
Polymers made from just one monomer
type are not the only option though. There are also polymers that are
formed when two or more types of monomer units react and combine. And chemists call polymers with
more than one type of monomer incorporated copolymers.
For example, the reaction below
shows the formation of a copolymer ester formed from a combination of two monomer
types. This reaction shows a diol reacting
with a dicarboxylic acid to form a copolymer. This copolymer is also more
commonly known as a polyester. Manufacturers use this material to
make bottles and mylar balloons.
It’s important to know that
copolymers can have all sorts of structures. And their monomers do not have to
alternate in an A-B-A-B type of fashion. So while copolymers can have many
different types of bonding arrangements, they must come from two or more types of
polymers.
So now, let’s answer the
question. Which of the following substances
cannot be classified as a copolymer? With the exception of answer choice
(E), all of the answer options have at least one A- and one B-type monomer. Answer choice (E) only has one
subunit type, represented by the letter A. But there is no second type of
monomer. So we can correctly choose answer
choice (E).
