Topic 4 - Plastics

Views:
 
Category: Education
     
 

Presentation Description

No description available.

Comments

By: deadmanchest20011 (29 month(s) ago)

slamax!!sir hw can i'll b able to dwnload it????

By: ambot777 (42 month(s) ago)

thank you so much.

By: mschongkong (42 month(s) ago)

Hi I have made the presentation downloadable for now, Because the presentaion is not from me but from my students, this is the reason it was not available.

By: ambot777 (42 month(s) ago)

how can i download this?

Presentation Transcript

P l a s t I c s : 

P l a s t I c s By: Alison Luk Beatrix Lee Sally Campbell

Bonds in Plastics : 

Bonds in Plastics Covalent Bond Atoms share electrons in outer shell Strongest type of bonding Primary bonds in plastics

Thermosets and Thermoplastics : 

Thermosets and Thermoplastics Macromolecules – long chains of molecules Primary bonds – strong forces of attraction Secondary bonds – weak forces of attraction Thermosetting plastic Thermoplastic

Elasticity in thermoplastics : 

Elasticity in thermoplastics Weaker secondary bonds enable elasticity When under load within elastic limit, plastic can return to original form When load exceeds elastic limit, plastic deforms Some plastics also suffer from creep

Heating thermosets and thermoplastics : 

Heating thermosets and thermoplastics Recyclable

Properties of Plastics : 

Properties of Plastics Thermosetting plastic Thermoplastic Stronger More brittle Low tensile elongation Low viscosity (in liquid form) Higher temperature resistance Tougher (more impact strength) Less brittle High tensile elongation High viscosity (when liquid)

Polypropene/Polypropylene : 

Polypropene/Polypropylene Chemical-resistant containers e.g. Food Containers Hinges Fishing nets Medical equipmente.g. syringes Bottle crates

Polyethene/Polyethylene : 

Polyethene/Polyethylene LDPE: Packaging film Carrier bags TV cable Toys Detergent 'squeezy' bottles HDPE: Bottles Pipes Bowls Milk Crates Buckets

Polyurethane(can be thermoplastic or thermoset) : 

Polyurethane(can be thermoplastic or thermoset) Skateboard wheels Varnish Shoe soles Artificial sponges Cushioning & buoys in boat hulls

Urea-Formaldehyde : 

Urea-Formaldehyde Electrical fittings i.e. plugs Textiles i.e. clothing Wood adhesives

Slide 11: 

Disposing Plastics Dumping in Landfills Destroys the environment Non biodegradable Hazardous to wildlife Via Incineration Process Releases harmful toxic fumes into the atmosphere RECYCLE Designated recycling bins Plastic Resin Symbol easily distinguished faster recycling process