1. Polymers and their Properties C2: Chapter 2

2. Learning Objectives To be able to list and state uses of commonly used polymers To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers To be able to explain how the properties of polymers arise CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers

3. Starter Activity What do you remember from year 10? Polymers What is a single unit of a polymer called? Where do polymers come from? Can you define a polymer? Can you name some examples? 5 minutes

4. Polymers Polymers are made of monomer units Monomers undergo a polymerisation reaction and make polymers A polymer is a substance made from large molecules made up of many repeating units (monomers). LO1:To be able to list and state uses of commonly used polymers

5. Polymer Party Video Draw and fill in this simple chart as we watch a short video on polymers LO1:To be able to list and state uses of commonly used polymers Name of PolymerName of MonomerUses of Polymer

6. Natural vs. Synthetic Polymer Quiz NATURALSYNTHETIC LO1:To be able to list and state uses of commonly used polymers WOOL Carpert and Clothing LATEX Gloves, Condoms, Balloons POLYESTER Clothing, Seat Belts, Blankets NYLON Clothing, Fishing Lines SILK Clothing, upholstery and parachutes TEFLON Cable insulator, non stick pans

7. Polymer Research Activity Use the exercise books to complete the table 15 minutes EXTENSION Polymer Exam Question LO2:To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers

8. Peer Mark LDPEHDPEThermosofteningThermosetting Structure Low density branched chains which prevent tight packing High density straight chains which allow for tight packing Long straight chains that are all tangled Rigid structure with fixed chains Bonding and Forces Weak intermolecular forces Strong intermolecular forces Weak intermolecular forces that are easily broken with heat Strong covalent bonds linking chains together (cross links) don’t break when heated Formation High pressure (and trace oxygen) Low pressure (and catalyst at 50 o C) N/A Properties Weak structure with low melting points Strong structure with high melting point Soften when heated and can be remoulded Do not soften when heated, just burn. LO2:To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers

9. Key Question How do the properties of polymers arise? What do the properties depend on? Discuss with the person next to you HINT: LOOK AT YOUR TABLE, think about our lesson on alloys! LO3:To be able to explain how the properties of polymers arise 2 minutes

10. Polymer Properties The properties of a polymer depend on: – The monomers used to make it – The conditions under which the polymer is made – The strength of the forces between molecules LO3:To be able to explain how the properties of polymers arise

11. Prediction Challenge Based on your understanding of intermolecular forces and the structure of polymers, DRAW what you think thermosoftening and thermosetting polymers look like CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers 2 minutes

12. Thermosoftening vs. Thermosetting Thermosoftening Polymer chains are easy to separate Forces broken when heated When polymer cools forces pull the molecules back together Thermosetting Chains fixed together by strong covalent bonds Bonds stop the chains separating When heated strongly the polymer will burn/char. CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers

13. Plenary The polymer chains in a thermosoftening polymer form a web. The polymer softens at relatively low temperatures. Other polymers have strong bonds between their chains which form. We call these polymers. Covalent Thermosetting TangledCross Links tangled covalent cross links thermosetting 5 minutes