Plastics Mr Phillips

Oil Barrel

OIL REFINERY

Remember all plastics are polymers!! Polymers and Monomers All plastics are based on polymers: Created by bonding molecules together. A monomer is a relatively small molecule that can Chemically bond to other monomers, forming a polymer. A monomer is a molecule that is able to bond in long chains. Here is a monomer:          Here is a polymer:     Remember all plastics are polymers!! 

Remember: Many modern plastics are manufactured from oil. A MONOMER is a small molecule that combines chemically to other monomers to form a polymer Example - derived from oil - a hydrocarbon ethylene molecule (see opposite). Remember: Many modern plastics are manufactured from oil.

An ethylene monomer forms a ‘long chain monomer’ (below) This produces the polymer - polyethylene. A thermoplastic useful in the manufacture of 'plastic' bottles.

Plastic Groups

THERMOPLASTIC ELASTOMERS (TPE) Examples: ALSO CALLED THERMOPLASTIC RUBBER INTRODUCTION

THERMOPLASTIC ELASTOMERS (TPE) GENERAL PROPERTIES  Good tensile strength and are tear resistance. Resist chemicals and ink / paint adhere well to them. Good flexibility and resistance to compression. After bending, they will return close to their original shape / form. They can be reprocessed / recycled by raising the temperature above melting point. Reformed during the melting process They can be extruded, blow moulded and injection moulded. They can be remoulded if the temperature is raised until the TPE becomes soft and pliable.   MAIN DISADVANTAGES  High cost compared to other plastics. If they are Heated relatively high temperature, they tend to lose their ‘rubbery’ property.TPEs Tend to ‘creep’. (tendency to move and deform when under the influence of stress, such as sustained pressure and temperature)  GENERAL USES  Used widely in the automotive industry, replacing common elastomers (rubber) because of their ability to resist wear and tear. Casing of electronic devices (TV remote controls)

Complete two worksheets