project 2 plastics
TRANSCRIPT
Project 2- Plastics By Ana Díaz Sánchez Ángela Oliva Jiménez María Osuna Galisteo Paula Parra García-Bravo
Explain the first and the second steps of the process of obtaining plastics:
•1st sourcing of raw materials;
• Coil, oil and natural gas.
• Before the manufacturing process, raw materials often are altered.
• They can be from
• Crude oil is processed to increase the concentration of metal, then, additional processes are used to produce the plastic.
STUDENT 1
Animal originPlant originMineral origin
• 2nd Synthesis of monomers:
• Monomers: structural repeated unit.
• Small subunits that ultimately link together to form larger molecules are called monomers.
• Monomers are taken from plastics by chemical reactions.
·Explain the following methods of shaping and finishing plastics. Mention at least one object that could be made with each technique:
Thermocompression
·Two metals, e.g gold, are brought into contact applying force and heat simultaneously.
Ashtrays are made by thermocompression
Extrusion moulding
• Extrusion moulding is a manufacturing process.
• Granules melt into a liquid.
• Forming a long 'tube like' shape
Hoses are made by extrusion moulding
Blow Molding• Manufacturing process by which hollow plastic parts are
formed.
• Begins with melting down the plastic.
• The parison (tube like piece) is then clamped into a mold and air is blown into it.
Bottles are made by blow molding
3rd Synthesis of the basic polymer
Polymerization: Process in which many monomers are combined.
• Chain-growth polymerization: monomers are added to the chain one at a time only
• Step-growth polymerization: chains of monomers may combine with one another directly
STUDENT 2
Explain the third and the fourth steps of the process of obtaining plastics
4th Incorporation of additives
Additives: • Materials mixed with polymer to make plastics.
• Additives turn basic polymers in to useful plastics
• Additives make plastics clean and healthy, safe, work longer, look good…
Some types of additives:
• Antioxidants: to protect the polymer from degradation by ozone or oxygen
• Ultraviolet stabilizers: to protect against weathering
• Plasticizers: to increase the polymer’s flexibility
• Lubricants: to reduce friction problems
• Pigments: to give the plastic colour
Explain the following methods of shaping and finishing plastics. Mention at least one object that could be made with each technique
• Injection molding: It is the process by which a material is injected into a mould so it takes the mould’s form.
• Foam molding: It is the process which combines plastics and gas.
• Vacuum forming: Sheets of plastic are heated, streched into a single-surface mold and pressed against a mold by a vacuum.
• Calandering: This process consist of multiple hard pressure rollers used to give form and smooth a material (plastic)
Provide information about the following properties in plastic material Physical properties:
• Electrical conductivity: Ability to transport an electric charge.
• Thermal conductivity: Capacity of a body to store thermal energy.
• Expansion: The size and the temperature increase.
• Density: Mass per unit of volume.
• Melting point: State in which the temperature changes from solid to liquid. This process depends on pressure.
• Fussibility: State in which a material melts. Refractory materials are those that melt at high temperatures.
STUDENT 3
Mechanical properties• Types of stress: • Traction: Two opposite forces that pull it to the sides• Compression: Two opposite forces that pull it to the centre.• Bending: Forces that bend the object.• Shearing: Deformation of a material in two opposite directions. • Torsion: Spin around it axis.
• Plasticity: Capacity os a material to undergo a deformation when it is compressed.
• Elasticity: Flexibility of an object.• Malleability: Ability to deform a under pressure object.• Ductility: Ability of a solid material.• Resistance: Ability to undergo a stress without breaking.• Hardness: Ability and resistance without scratching.• Weldability: Ability to join with another materials using heat.
Chemical properties
• Permeability,NO: Property of being permeable.• Solubility,NO: Ability to mix in a homogeneous mixture.• Combustibility,YES: Ability to burn.
Biological properties • Reciclability,YES: Ability to transform materials into useful
objects.• Toxicity, YES: When a material is affected by toxic substances.• Biodegradability, NO: Effect of environmental decomposition. •
Plastic materials are classified in three groups:
Thermosetting polymer (thermoset): • Petrochemical material
• Liquid or malleable prior
• Others are solid (molding compound used in semiconductors and integrated circuits)
STUDENT 4
Thermoplastic (thermosoftening plastic):• It is a plastic material (polymer)
• High molecular weight
Elastomers (elastic polymer):• It has viscoelasticity
• Very weak intermolecular forces
Bibliography• http://www.investopedia.com/terms/r/rawmaterials.asp• http://
global.britannica.com/EBchecked/topic/369072/materials-processing• http://
www.finetechusa.com/bonders/technologies/thermocompression.html• http://en.wikipedia.org/wiki/Thermocompression_bonding• http://en.wikipedia.org/wiki/Polymer#Polymer_synthesis• http://www.bpf.co.uk/plastipedia/additives/default.aspx• www.thomasnet.com/about/thermoset-plastics-61020277.htmls• www.ehow.com/about_5545184_properties-thermoplastic.html• www.adhesiveandglue.com/elastomer.html• www.dupont.com/products-and-services/plastics-polymers-resins/elastome
rs/articles/guide-to-elastomer-properties.html