Chemistry - 11 Polymers

Natural polymers [3]:

- polynucleotides (DNA)
- polypeptides (proteins)
- carbohydrates

Polysaccharide

carbohydrates that are made up of more than two monosaccharides

Amino acid structure

a carboxyl group, amine group, and R group

R group

a functional group that defines a particular amino acid and gives it special properties

How do amino acids join?

condensation polymerisation

Dipeptide

two amino acids bonded together

Functional group of polypeptides

peptide linkage

Peptide linkage

bond between amino acids in a protein

Polypeptides are ... while polyamides are ...

natural, synthetic

Basic group in an amino acid

amine group

Acidic group in an amino acid

carboxyl group

Starch

storage polysaccharide consisting entirely of glucose.

Cellulose

polysaccharide consisting of glucose monomers

Glucose structure

Starch structure

all the same way up

Cellulose structure

alternating ways up

Polypeptide general word equation

variety of amino acid monomers → protein polymers + water

Nucleotide

monomer of nucleic acids

Components of a nucleotide [3]:

- pentose sugar
- phosphoric acid
- organic base (variable)

Bases in DNA [4]:

- adenine
- thymine
- cytosine
- guanine

A combines with...

T

C combines with...

G

Between C and G, there are...

3 hydrogen bonds

Between A and T, there are...

2 hydrogen bonds

DNA structure

double helix

Monomer

small chemical unit that makes up a polymer

Polymer

large compound formed from combinations of many monomers

Polymer of alkene

poly(alkene)

Addition polymerisation

combination of a large number of monomers to form a single chain

Why are polyalkenes unreactive?

as they are saturated and contain only single covalent bonds

How does addition polymerisation work?

the C=C double bond is 'broken' so that either end can bond to another carbon

Advantages of polyester fibres [2]:

- hard-wearing
- less wrinkling

Advantages of nylon fibres [3]:

- lightweight
- less wrinkling
- non-absorbent (dries quickly)

What are the products of condensation polymerisation?

condensation polymer + small molecule (H₂O or HCl)

Two types of condensation polymerisation [2]:

- between two different monomers with different functional groups on both ends (xAx + yBy)
- between the same monomer with two different functional groups on either side of each (xAy + xAy)

Diol

an alcohol containing two -OH groups (e.g. butane diol)

Dicarboxylic acid

a carboxylic acid containing two -COOH groups (e.g. butane dioic acid)

Carbon backbone

the chain or ring upon which the remainder of the molecule is built

Polyesters are made with... [2]

- a diol
- a dicarboxylic acid

Diol + dicarboxylic acid

condensation polymer + water

Amine group

NH₂

Amino acid

monomer of protein

What does the dicarboxylic acid give to the water molecule in condensation polymerisation?

-OH

What does the diol give to the water molecule in condensation polymerisation?

-H

Addition polymers are ... while polyesters are ...

non-biodegradable, biodegradable