Repurposing LNG terminals for Hydrogen Ammonia: Feasibility and Cost Saving
Presentación 2
1. Student 2
Explain the third and the fourth steps of the process of
obtaining plastics
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
2. 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
3. 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.
4. • 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)
