Embedded Files
What are polymers? I'm gonna tell you all nformation that I know about these materials.
THREE categories:
THERMOSETTING
THERMOSETTING
polymers that cannot be reheated/formed.
Examples - Formaldehyde, resin.
THERMOPLASIC
THERMOPLASIC
polymers tha can be reheated/formed.
Examples - PET, PS, PP, PMMA.
ELASTOMERS
ELASTOMERS
Soft polymers with elastic properties.
Examples - Rubber, Elastic, TPE.
Polymers are made up of long chain molecules containing carbon, hydrogen and oxygen atoms, along with other chemicals such as chlorine and fluorine.
Polymers occur naturally in nature and can be derived from plant and animal sources.
They include:
1) Casein (derived from milk) which is still used to make buttons,
2) Horn,
3) Resin (from trees)
4) Cellulose from plants - In the case of Cellulose it is mixed with acetic acid to make Cellulose acetate which is still used today for OHP slides.
There are bio polymers and synthetic polymers (differences between them are time of biodegradabling and including ethanol).
Thermoplastic.
Thermoplastic.
Chemical chain.
Elastomer.
Elastomer.
Chemical chain.
Thermoset.
Thermoset.
Chemical chain.
Thermoplastic polymers:
Polymers have some unique properties which make them particularly useful for modern day applications.
1) They are good electrical and thermal insulators
2) They have a good strength to weight ratio. This does not mean they are strong in the same way as steel but that they have good strength compared to their weight.
3) They generally have good atmospheric and chemical resistance.
4) They have fairly low melting temperatures (Thermoplastics only)
5) They are lightweight
6) They can be self coloured, opaque or transparent and are self finishing.
7) They are quite hygienic and are water resistant.
8) They can be enhanced with the addition of fillers, plasticisers and stabilisers to make them more flame retardant or anti static etc.
A table of recyclable/reformed polymers.
Thermosetting polymers:
Thermosetting plastics are polymers that cannot be reheated and reshaped. When the plastic is formed cross linking takes place across the long chain molecules which cannot be broken down by heat. While this means these types of plastic are good for situations where they will be subjected to heat and electricity, these types of plastics cannot be recycled.
POLYESTER RESIN.
Brittle but strong with fibres such as glass or carbon. Used to make boat hulls and car body parts.
EPOXY RESIN.
High strength when combined with fibres. Also used as an adhesive (Araldite).
UREA FORMALDEHYDE.
Used for white electrical fittings.
MELAMINE FORMALDEHYDE.
Used for worktops surfaces.
This is a second table with properties and applications:
Page updated
Google Sites
Report abuse