PROJECT 2: PLASTIC MATERIALS

-Elena Garijo

-Daniel Navarro

-Cristina Puerta

-Renata Szabo

STUDENT 1:*Sourcing of raw materials:

Raw materials can be of:

-Vegetal origin from tropical tres line, cotton, wood…

-Animal origin wool, fur and leather

-Mineral origin plastics are composed of pretoleum, carbón and fossil fuel gold, plastics, iron…

*Synthesis of monomers:

Monomers basic substances.

Consists of the extraction of monomers from raw materials chemical reactionspetrochemical industries ethylene, propylene

*Methods of shaping and fishing plastics:

-Thermocompression thermosetting plastic products

-Extrusion molding →pipes,bars and laminated profiles.

Plastic → chute into a heat pipe → the worm screw makes the plastic move forward → plastic goes to an opening which shapes it → cooling chamber → cool and hardened → measure.

-Blow molding → containers for liquids.

It is put in a mold → pressurized air → plastic sticks to the walls → when it is cooledand hardened → opens and the piece is removed.

STUDENT 2:*Synthesis of basic polymers:

Plastics are prepared by mixing components

When they are mixed together subjected to chemical processes (polymerization,

polycondensation, polyaddition) modifies their properties, making new materials in grains, resins, flakes…

*Additives:

These are chemical products added in the precise proportions to give the polymer properties like thermal and electrical conductivity, resistance to fire, rigidity, flexibility, etc.

-Dyes or pigments: give it color.

plasticity

-Plasticizers: improves

the shine on the surface.

-Antistatic agents: Reduce static electric charge in order to the dust and dirty not to stick

-Fireproof or fire-retardant agents: delay formation of flames.

UV radiations

-UV stabilizers: Protect it decomposition

atmospheric phenomena

-Fillers, reinforcements, and lubricants: improve and facilitate

-Mold release agents: make the piece come out of the mold easily.

-Antioxidants: prevent reactions with oxygen.

mechanical properties

manufacturing process

*Methods of shaping and finishing plastics:

-Injection molding is used to make objects with complex shapes.

-Foam molding is used to make packaging, pillows, and sponges.

-Vacuum forming is used to make glasses, packaging, and boxes.

-Commercial shapes is used for commercial use, plastics are presented in bars.

Injection molding Vacuum molding

Foam Calendaring

Molding

STUDENT 3:

physical

mechanical

4 types of properties:

chemical

biological

*Physical properties:

-Electrical conductivity: let current flow through it.

plastic low conductivity

A. Heeger, A. McDiarmid, H. Shirakawa Nobel prize in 2000 developed polymers thatconduct electricity

-Thermal conductivity: let hit pass through it.

Plastics low thermal conductivity

-Density: amount of material mass per unit of volume plastic is low

low weight

-Expansion: relative variation in the dimensions of a material because of temperature.

SOLID LIQUID LIQUID SOLID

Plastics High coefficient of expansion

Reinforced plastics low coefficient of expansión

-Melting Point: temperature when a solid becomes a liquid

-Fusibility: amount of heat needed to melt materials

200ºC later

*Mechanical properties:

traction

compression

-Types of stresses: bending

shearing

torsión

-Traction: a material is subjucted by two opposing forces that pull on it.

It gets broken if it

is very strong

-Compression: two opposite forces that push on it.

it can be broken

-Bending: subjected by two forces trying to bend it.

-Shearing: subjected by two opposite forces acting in different pints close to each other and try to cut the material.

shearing

-Torsion: subjected by two forces, twisting it by an axis

Elasticity: is the ability of a material to deform when it goes under the force of a stress

Limit point yield point

Plasticity: ability of a material to remain deformed by a stress when it is removed.

-Malleability: ability of a material to be permanently deformed under compression.

-Ductility: ability of a material to be permanently deformed under traction.

Used to make bars

and wires

-Resistance: ability of a material to undergo stress without breaking.

-Hardness: ability of a material to resist being scratched or punctured.

-Weldeability: ability of a material to join solidly with another when heated.

Weldability Hardness

*Chemical properties:

-Permeability: ability of a material to let fluids to flow throw them.

Normally plastics are impermeable

-Solubility: ability of a material to mix homogeneously with

another substance solvent

-Combustibility: ability of a material to burn.

Plastics burn easily but is polluting

*Biological properties:

-Recyclability: ability to produce from a used product a new one.

Recycle separate different materials

-Toxicity: ability of a material to produce

negative effects on

living organisms.

-Biodegradability: ability of

a material to decompose.

STUDENT 4:*Plastic materials are classified in three groups:

-Thermosetting : They are petroquemical materials and they can´t deform easily , it can onlydeform with heat and if it is at 170 °C.

*Thermosetting they are divided in five groups:

-Phenolic resins: They are hard, insoluble, resistant to very high temperatures.

You can use it to buttons, switches, handles, and kitchen utensil handles.

-Ureic resins impermeable to liquids.

You can use it for electrical accessories, handles, door and drawer knobs,bottle caps, plates, cups, and pans.

-Melamine resins impermeable to liquids and elastic.

You can used it for household furniture.

Polyester resins they are good electrical and thermal insulators ,also mixed with a catalyst. Mixed with fiberglass, they are used in tanks, bodywork of vehicles.

-Epoxy resins They are good

electrical insulators, resistant to humidity and high temperatures.

We can used it in varnishes, coatings for word, plastics, and electrical and electronic systems.

-Thermoplastics: They are soft and you can deformed with heat

They are divided in some groups:

transparent, tough, resistant to mechanical stress and oils

Polyethylene terephthalate Uses for carbonated beverages, oils, water, chemical products

Objects made of polyethylene terephthalate are marked with these symbol

Tough and resistant to mechanical stress and chemical agents.

Polycarbonate Fabrics, household utensils, bearings, gears, screws, household appliance

parts, and electrical connectors.

Objects made of polyamide do not have a specific symbol

It is fireproof, and resistant to chemical products and high temperatures.

Teflon or Polytetrafluoroethylene

Nonstick coatings, joints, and insulation for high-temperature cables

*Elastomers: They are materials that are very elastic.

They are impermeable and a good electrical and acoustic insulator.

We use them for natural rubber products.

-Elastomers is divided in several groups:

It is resistant to organic liquids is impermeable

and a good electrical and acoustic insulator.

Synthetic rubber Tires, solid wheels…etc

In 1887 John Boyd Dunlop,he was an Scottish veterinarian, and he

invented the first air chambers for bicycles of the time and these is how tires were invented.

John Boyd Dunlop first air chambers for bicycles.