Polymer processing
Michal Vonka
Institute of Chemical Technology in Prague
Department of Chemical Engine...
Outline
• Polymerization
• Polymer structure and properties
• Polyethylene terephthalate
• Polymer processing and ...
Creation of polymer –
polymerization
Reaction mechanism :
reaction
Monomer + monome...
n is virtually EVERYTHING
Chain properties:
• Length
• Branching
Material properties:
• Crystallinity
• The Chain Length ...
Polymer chains and semi-crystallic
structure
Entanglement
...
Chain Length Distribution
Typical chain length distribution
...
• Synonym to POLYESTER
PET
• Many forms and industrially produced types (CLD, addit...
Polycondensation of PET:
Dimethylphtalate
Ethanediol
Methanol
...
Injection molding – PET Mold?
Molding?
prefabricate & the lid
...
Blow molding – the bottle
Furnace
High pressure injector
...
Recycling
• Sorting the types of polymers
• EXTREME costs vs. ECOLOGY
Two ways:
– Chemical way (decomposing to process
...
Degradation and health risks
• Phthalates
– Teratogenes?
• Light degradation
• Thermal oxidation
Stoichiometric
No...
Summary and conclusions
• Polymer : chains & • Degradation
semi-crystalic • Health risks
structure ...
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Polymery Cvut V1

Lecture about PET bottles
Published on: Mar 4, 2016
Published in: Education      Business      Technology      
Source: www.slideshare.net


Transcripts - Polymery Cvut V1

  • 1. Polymer processing Michal Vonka Institute of Chemical Technology in Prague Department of Chemical Engineering Group of Polymer Reactor Engineering
  • 2. Outline • Polymerization • Polymer structure and properties • Polyethylene terephthalate • Polymer processing and blow molding • Injection molding • Recycling and further usage • Health risks • Conclusions and summary
  • 3. Creation of polymer – polymerization Reaction mechanism : reaction Monomer + monomer Dimer reaction Dimer + something Active chain n-times repeated Loosing of chain activity Dead polymer chain (product?) n is important
  • 4. n is virtually EVERYTHING Chain properties: • Length • Branching Material properties: • Crystallinity • The Chain Length Distribution (CLD) • Gloss • Glass transition temperature • Melting point • Impact resistance • Young modulus
  • 5. Polymer chains and semi-crystallic structure Entanglement semi-cystallic polymer 10 nm spherulite lamellae and amorphous phase curving and branching of 10 µm lamella
  • 6. Chain Length Distribution Typical chain length distribution Number of species Affected properties : • Crystallinity • Glass transition temperature • Melting point • Gloss • Impact resistance • Young modulus • Etc… PET example: particle size: 0.5 - 10 micron (gloss) Young modulus: 2800 – 3100 MPa 100 pm size of carbon atom
  • 7. • Synonym to POLYESTER PET • Many forms and industrially produced types (CLD, additives) • Additives – color, gloss, conductivity, tensile strength, impact resistance • Usage: synthetic fibres (60%), beverage, food and other liquid containers (30%), combination with glass fiber • Year production 5 000 kt/year • Price 0.5–1.25 !/kg • Glass transition temperature ~ 75 °C • Melting point 250 – 270 °C
  • 8. Polycondensation of PET: Dimethylphtalate Ethanediol Methanol Polyethylene terephthalate
  • 9. Injection molding – PET Mold? Molding? prefabricate & the lid Molten Injector (230 – 250 °C) polymer Mold (5 – 20 MPa) • Mass production vs. cooling rates of the mold • More layers
  • 10. Blow molding – the bottle Furnace High pressure injector PET prefabricate in the moving bed • Mass production (100 000 pc / day) • Attaching the lid
  • 11. Recycling • Sorting the types of polymers • EXTREME costs vs. ECOLOGY Two ways: – Chemical way (decomposing to process intermediates and adding into the fresh production – lowering quality) – Mechanical way (cleaning and new usage) Mostly for more-layer PET
  • 12. Degradation and health risks • Phthalates – Teratogenes? • Light degradation • Thermal oxidation Stoichiometric Non-stoichiometric Small particles of carbon (2-7 microns) Ketones and aldehydes (irritants, carcinogens) C
  • 13. Summary and conclusions • Polymer : chains & • Degradation semi-crystalic • Health risks structure • Usage • The molding conditions are essential to the final product • Additives • Difficult recycling ???