slime practical place 40 cm 3 of pva solution into the plastic cup. measure out 10 cm 3 of borax...

Slime Practical

• Place 40 cm3 of PVA solution into the plastic cup.

• Measure out 10 cm3 of borax solution and add this to the PVA solution.

• Stir until the slime forms.

L10 Polymers

Learning Objectives:

1.Describe what a polymer is.

2.Describe the process of polymerisation.

3.Describe the properties and uses for polymers.

Drpsg polymerisation

What is a polymer?• A polymer is a long chain molecule that is formed from

small molecules linking together.

• poly = many

• Polymers are made from monomers.

monomer polymer

How are polymers made?

• Polymers are made from alkenes.

• (Remember, one of the products from cracking crude oil is alkenes)

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H


C C

H

HH

H

Take 3 ethene molecules - C2H4


C C

H

HH

H

C C

H

HH

H



C C

H

HH

H

C C

H

HH

H

C C

H

HH

H


Each one is unsaturated – it has a double Covalent carbon – carbon bond


C C

H

HH

H

C C

H

HH

H

C C

H

HH

H


To make polymerisation easy to understand draw the double bond horizontalAnd put everything else above and below


C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

Open the double bond

Imagine opening the double bond so it Forms a new carbon – carbon bond


C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

Break the double bond, join it to the next carbon in the chain



C C

H

HH

H

C C

H

HH

H

C C

H

HH

H



This is polyethene with 3 units in – actual examples have 1000’s of units of ethene in


Overall Equation

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

Ethene, a monomer

Poly(ethene), a polymer


Different representation

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

C

H

H

C

H

H

* *n

the number of repeat units

is shown by n . (* not needed)

Ethene – double bond - turns bromine water from orange to colourless

Poly(ethene) – no double bonds No effect on bromine water

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

C C

H

HH

H

Naming

•Put “poly” in front of the monomer name.

Formula

•Draw the monomer WITHOUT the double bond.

•Draw bonds out to the sides and put in brackets.

•Put an “n” in subscript after.


propene – C3H6

C C

CH3

HH

H


propene – C3H6

C C

CH3

HH

H

C C

CH3

HH

H


propene – C3H6

C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H



C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H




C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H



This is polypropene with 3 units in – actual examples have 1000’s of units of ethene in


Overall Equation

C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H

Propene

Poly(propene)



C C

CH3

HH

H

C C

CH3

HH

H

C C

CH3

HH

H

C

H

CH3

C

H

H

* *n


is shown by n .


Take 3 fluoroethene molecules

C C

F F

FF

C C

F F

FF

C C

F F

FF

C C

F F

FF

C C

F F

FF

C C

F F

FF


C C

F

HH

H

C C

F

HH

H



C C

F

HH

H

C C

F

HH

H

C C

F

HH

H




Overall Equation

C C

F

HH

H

C C

F

HH

H

C C

F

HH

H

C C

F

HH

H

C C

F

HH

H

C C

F

HH

H

Fluoroethene

Poly(fluoroethene)



C C

F

HH

H

C C

F

HH

H

C C

F

HH

H

C

H

F

C

H

H

* *n


is shown by n .

Properties of Polymers• The properties of polymers depends on what monomers

are used.• Scientists can make new polymers with specific

properties. • Usually polymers are stretchy and can be moulded.• Plastics are a type of polymer.

Problems with polymers• Polymers are very useful materials.

• However, they are not biodegradable.

• This means that polymers do not break down.

• Plastic waste can remain in landfills for hundreds of years!

HW: Extended Writing

• Describe what a polymer is and how polymers are formed. Draw an example of a polymer and describe why they are so useful.


slime practical place 40 cm 3 of pva solution into the plastic cup. measure out 10 cm 3 of borax...

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