PLASTICS

1. By: Jesús Castillo, Bruno Koster and Sergio Vicente.

2. Student One
 Raw materials: COAL, NATURAL GAS, MINERALS,
PLANTS and CRUDE OIL.
 With the synthesis of monomers you obtain a
polymer.

3. METHODS.
 Thermocompression: Ex: doorknob

4. METHODS.
 Extrusion molding: Ex: tubes

5. METHODS.
 Blow molding: Ex: bottle

6. Student Two
 SYNTHESIS OF BASIC POLYMERS:
 Plastics change shape and for.
ADDITIVES:
 Chemical products to give plastic new qualities.

7. INJECTION MOLDING:
Process consisted in injecting
materials into a mould.

8. FOAM MOLDING:
 Is a process in which you make soft plastics.

9. VACUUM FORMING:
 Is a process in which you apply heat and absorb the
air inside.

10. CALENDERING:
 A sheet of plastic passes between two rolls.

11. Student Three
PHYSICAL PROPERTIES OF PLASTIC
 Electical conductivity:Capacity of a material for
allowing the electric current to pass.
 It has a high capacity of insulation.
 Used for protecting the wires.
 Thermal conductivity:It describes the behaviour of the
polymers against the action of heat

12. PHYSICAL PROPERTIES OF PLASTICS
 Density: Discovered by Arquimedes. (not for plastics)
Low Density Polyethylene also known as LDPE
Low density polymer
High thermal , chemical resistance.
 Expansion:Plastics expand if you increase their
temperature.
 Melting point:If the plastic is made of LDPE the melting
point would be 150·c
If the plastic is made of HDPE the meltin point would be
135·c

13. MECHANICAL PROPERTIES OF PLASTICS
 There are different types of stress:
Traction: The resistance to traction is the highest effort
a material can resist
Compression: Mold because of compression is the
oldest.You put a plastic on a mold with a cavity
Bending:You can bend a plastic by using an electric
resistance
Shearing:
Torsion: A plastic would be resistance to torsion if you
can bend the plastic without breaking it.

14. MECHANICAL PROPERTIES OF PLASTICS
 Elasticity: Plastics have a high capacity of elasticity.
Used for wheels
Malleability:When you can deform a plastic althought
it is cold.
Ductility:When plastic can be elongated with out
breaking.
Hardness:Is the capacity for penetrating in plastic.
Weldability:The ability of welding plastics depends on
time, temperature and pressure and the design of the
plastic

15. CHEMICAL PROPERTIES OF PLASTIC
 Permeability: Is the ability of passing through a solid
without changing its structure. A plastic bag is NOT
permeable.
Solubility: Plastics do not have the ability of solubility ,
except polyethenol and polyalcohol.
Combustibility: Plastic , when it reaches certain
temperatures , can be defored or melted.

16. BIOLOGICAL PROPERTIES OF PLASTIC
 Recyclability :Is the process of recycling plastic , and
making other new products.
 Toxicity:

17. BIOLOGICAL PROPERTIES OF PLASTIC
 Biodegradability : Biodegradation of plastics by
microorganisms and enzymes seems to be the most
effective process.

18. Student Four
 Thermosetting
Contains polymers
Cross-linking process eliminates remlting in a product
Improve meterials chemical properties
Provides chemical resistance , heat resistance and
structural.

19. THERMOSETING

20. THERMOPLASTICS
 Soften heated and become more fluid
 They can be remolded and recycled
 High strength, shrink resistance , easy weldability

21. ELASTOMER
 Polymer with viscoelasticity
 Weaker intermolecule forces
 It has a thin structure , slightly reticulated.