Plastics And Polymers.

Learning Objectives

• To show pupils how the properties of a material are dictated by the materials molecular structure.
• To show pupils what the molecular structure of a plastic looks like.
• To show pupils that some materials do not behave as predicted by the laws of physics. 

Where this fits into the Technology Syllabus Key Stage 3 Strategy, Making high quality products sub skill.
“ pupils should apply their knowledge of the characteristics of materials when creating solutions”

Content.

• Pupils are shown the PowerPoint presentation that shows how long chain molecules call polymers form the basis of many man made and natural materials.
• They see how molecules form the basis of these polymer structures.
• Pupils perform two experiments with PVA glue and Borax solution.
• They use these solutions to form a plastic like substance then explore the properties of the materials they have produced.
• Pupils see how the molecular structure of the material affect its physical properties.

Resources

• Borax solution (now sold as an environmentally friendly cleaning product)
• PVA glue.
• Water.
• Plastic cups or small containers
• Stirrer
• Spoon to measure
• Aprons
• Access to a computer running Microsoft PowerPoint.

Safety Issues.

• The Borax solution has to be made using boiling water; this should be done by staff and the solution left to cool.
• The experiment involves using liquids and as such their may be a danger from slipping if spilt.

Estimated Time To Complete The Exercise – 40 minutes.