Synthetic & Natural Polymers Flashcards

All 24 cards in this deck

What is addition polymerisation?

Many small molecules (monomers) join together to form very large molecules (polymers), with the polymer as the only product.

Which functional group must a monomer contain to form an addition polymer?

A C=C double bond (the monomer is an alkene).

Why does the repeating unit of an addition polymer contain the same atoms as the monomer?

Because no other molecule is formed in the reaction — every atom of the monomer ends up in the polymer.

What are the steps to draw the equation for the formation of an addition polymer from an alkene monomer?

e.g. ethene $\mathrm{CH_2{=}CH_2}$

1. Write $n$ in front of the monomer's displayed formula: $n$ ethene with C=C.
2. Change C=C to a single C–C bond and extend a bond from each end carbon through the brackets.
3. Write $n$ after the bracket: poly(ethene) repeating unit $\mathrm{-CH_2-CH_2-}$.

What are the steps to deduce the monomer from a given repeating unit of an addition polymer?

e.g. repeating unit $\mathrm{-CH_2-CHCl-}$

1. Take one repeating unit from inside the brackets.
2. Remove the two bonds that pass through the brackets.
3. Change the C–C bond in the backbone to C=C: monomer is chloroethene $\mathrm{CH_2{=}CHCl}$.

True or false? In addition polymerisation a small molecule such as water is lost as the monomers join.

False. No other molecule is formed — the polymer is the only product.

What is condensation polymerisation?

Monomers with two functional groups join together, usually losing small molecules such as water.

Which two types of monomer react to produce a polyester?

A diol (two –OH groups) and a dicarboxylic acid (two –COOH groups).

Which small molecule is lost when a diol polymerises with a dicarboxylic acid?

Water, $\mathrm{H_2O}$.

How many products are formed in addition polymerisation compared with condensation polymerisation?

Addition: one product (the polymer only). Condensation: two products (the polymer and a small molecule such as water).

True or false? The monomers used in condensation polymerisation must contain a C=C double bond.

False. They contain two functional groups, such as –OH or –COOH; C=C is needed for addition polymerisation.

Which two functional groups does an amino acid contain?

An amine group $\mathrm{-NH_2}$ and a carboxylic acid group –COOH.

What polymer is produced when amino acids react by condensation polymerisation?

A polypeptide.

What is produced when different amino acids are combined in the same polymer chain?

A protein.

Name the small molecule produced, as well as the polypeptide, when glycine polymerises.

Water ($\mathrm{H_2O}$).

True or false? A single amino acid can polymerise with molecules of itself because it has two different functional groups.

True. The $\mathrm{-NH_2}$ of one molecule reacts with the –COOH of the next.

What are the steps to deduce the repeating unit of a polypeptide from an amino acid?

e.g. glycine $\mathrm{H_2NCH_2COOH}$

1. Identify the $\mathrm{-NH_2}$ and –COOH groups on the monomer.
2. Join the $\mathrm{-NH_2}$ of one molecule to the –COOH of the next, losing $\mathrm{H_2O}$.
3. Repeating unit $\mathrm{-NH-CH_2-CO-}$, with bonds through the brackets and $n$ outside.

What does DNA stand for?

Deoxyribonucleic acid.

What is the function of DNA?

It encodes the genetic instructions for the development and functioning of living organisms and viruses.

Describe the structure of most DNA molecules.

Two polymer chains made from four different monomers, twisted into a double helix.

What is the general name for the four different monomers that make up DNA?

Nucleotides.

Which monomer are starch and cellulose made from?

Glucose.

Which monomers are proteins made from?

Amino acids.

True or false? The repeating unit of an addition polymer is drawn with a C=C double bond, just like the monomer.

False. The double bond opens up during polymerisation, so the repeating unit is drawn with single C–C bonds and two bonds extending through the brackets.