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Polymer Chemistry

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Top 10 List. Polymer products change our life significantly. Ties ... Nobel Prize winners. 1953 Herman Staudinger. 1974 Paul Flory. Top 2 High-volume Polymers ... – PowerPoint PPT presentation

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Title: Polymer Chemistry


1
????? Polymer Chemistry
  • ? ? ?
  • Jihperng (Jim) Leu
  • Fall Semester, 2004

2
Grading
  • 35 Report
  • 15 Presentation / Attendance
  • 25 Mid-term Exam
  • 25 Final Exam
  • 5-point bonus point if you provide me
    feedback/suggestion during this semester
  • (Final grade will be normalized based on 100
    points)
  • Class policy
  • NCTU Honor Code
  • Medical record is required for missing exams
  • Dozing.. is wasting your time in this class!
    STAND UP and stretch in the back of the
    classroom

3
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4
Top 10 List Polymer products change our life
significantly
  • Ties (Synthetic rubber)
  • Non-sticky pan (Teflon)
  • Polyethylene
  • Stocking (Nylon)
  • Polystyrene
  • PVF
  • PMMA
  • Silicone
  • Rayon
  • Piping (PVC)
  • We will review this list in the end of this course

5
Show and Tell
  • Compact Disk
  • Zipper bag
  • PVC tubing
  • Soda bottle
  • Jacket for ski
  • Rayon
  • Rubber

6
Introduction
7
History of Polymers
1927 PVC 1934 PE ICI 1934 Nylon Du
Pont Nobel Prize winners 1953 Herman
Staudinger 1974 Paul Flory
8
Top 2 High-volume Polymers
  • Polyethylene
  • 50M tons/yr (2003)
  • packaging, consumer goods, pipe, durable
    equipment and industrial machinery
  • PVC
  • 27M tons/yr (2002)
  • Building 56 Packaging 15 Consumer goods 10
    Electronics industries 9 Agriculture 5 Others
    5.

9
History of Polyethylene
  • Polyethylene, was discovered largely by accident
    in 1933 by scientists working for ICI. From
    1937 pilot plant work proceeded but only a small
    amount of polymer was produced. The first plant
    came into operation in September 1939 and the
    resultant product, named "Polythene" by ICI, was
    to have a major impact on the war effort. It was
    found that the long chain, low density white
    polymer could be extruded as film and coated
    around wires and cables to give greatly enhanced
    performance. Polythene was a superb insulator
    with high dielectric and low loss factor and was
    thus in great demand for submarine cables, radar
    applications, etc.Major production continued
    from 1942 and ICI licensed other companies
    thereafter in the production of high pressure
    polyethylene which produced the low density
    product - LDPE. However, the extreme conditions
    and costs for production coupled with low
    temperature softening, creep and stress cracking
    of LDPE limited the full potential of the
    polyethylene family of polymers in film blowing
    and injection moulding volume applications.The
    development of new improved conditions for
    manufacture and control of molecular structures
    was to create accelerating and dramatic changes
    in the growth of polyethylene and other
    polyolefin polymers. (See Karl Ziegler and Giulio
    Natta) The subsequent huge range of products,
    especially in packaging films and containers
    coupled with great design and production
    flexibility through controlled material
    properties, has affected almost every aspect of
    modern life
  • Source http//www.plastiquarian.com/polyethy.htm

10
Applications of some polymers
  • HDPE ??? gt
  • LDPE ??? ??? ??
  • ????(PS) ???? ?????
  • ????(PVC) bottles, window frames, pipes,
    flooring, wallpaper, toys, car seats, guttering,
    cable insulation, credit cards, and medical
    products such as blood bags, IV tubing and much
    more. ?? ??? ?? gt
  • ???(PU) ???????? ?????????
  • ??66 ????? ?? ????
  • PET ???
  • ???? (PC) ???????????????????????????????????????
    ???????

11
Basic Definition and Nomenclatures
  • Definition
  • Polymer A substance composed of molecules with
    many repeating units (gt 10,000)
  • (segments, monomers, repeating units,
    sub-units)
  • Monomer Staring material from which polymer is
    formed
  • Dimer, trimer, oligomer
  • Monomer vs polymer (one-unit vs many units)
  • Macromolecules large molecules (such as
    proteins, synthetic polymers, etc)

12
Natural Polymers
  • Proteins
  • enzymes, muscles, tissue, hair, wool, silk
  • Carbohydrates
  • polysaccharides, starch, cellulose, rayon
    (reconstituted cellulose)
  • Nucleic Acids - DNA, RNA

13
Classification by Use
  • Plastics ??
  • HDPE, LDPE, Lexan, plexiglass, teflon,
    polystyrene
  • Fibers ??
  • Nylon, orlon, kevlar, rayon
  • Elastomers ??
  • rubber, spandex, poly(urethane) foam
  • Coatings ??
  • paints, varnishes, enamels, formica,
    Poly(urethane)
  • Adhesives ???
  • glues, cement, "scotch tape", epoxy, Hair spray

14
Adhesives
  • Adhesives are polymer-based formulations used to
    bond two surfaces together. Adhesives can be
    either reactive (form chemical bonds) or adhere
    by physical (van der Waals, ionic, etc) bonds.
  • Modern adhesives are classified either by the way
    that they are used or by their chemical
    constituents.
  • Anaerobics - used to bond metal surfaces together
    when air is excluded. They are generally based on
    acrylic resins.
  • Cyanoacrylates - reactive cyanoacrylic adhesives
    that cure in the presence of moisture. They
    solidify in seconds.
  • Toughened Acrylics - general use, strong
    acrylic-based adhesive. It's applied as a
    two-part, resin/catalyst system.
  • Epoxies - adhesives consisting of epoxy resin and
    hardener. These one-part, or two-part adhesives
    are extremely strong and versatile.
  • Polyurethanes - fast-cure, two-part adhesives
    used for bonding glass-reinforced plastics.
  • Modified Phenolics - phenolic resins for bonding
    metal to metal, or metal to wood. They require
    pressure and heat to cure.
  • Hot Melts - semi-crystalline polymers that bond
    physically. Joints form quickly, but are not very
    strong.
  • Plastisols - poly(vinyl chloride) based
    dispersions that require heat to harden. Once
    set, the joint is tough and resilient.
  • Rubber Adhesives - solutions or latexes of rubber
    that solidify by loss of solvent. Do not give
    load-bearing joints.
  • Poly(vinyl acetates) - PVA emulsions for use in
    bonding porous surfaces. Used in the packaging
    industry.
  • Pressure Sensitive Adhesives - used for labels
    and tapes. They don't solidify, rather stay in
    the rubbery flow regime.

15
Polymer Nomenclature
In most cases poly monomer name Trade names
Acronyms Examples PMMA and Nylon PMMA
Poly(methyl methacrylate) PLEXIGLASSTM
NylonTM (Du Pont)
16
Homopolymers
17
Examples - Homopolymers
  • Polyethylene
  • Polypropylene
  • Polytetrafluoroethlyene
  • Polystyrene
  • PMMA
  • PVC
  • PVA
  • PEG
  • PET
  • Nylon
  • Assignment Chemical structure, Tg, modulus,
    applications
  • Due next Monday

18
Copolymers from different monomers
19
Skeletal structure
20
Classification of Polymers
  • Thermoplastics (heat/pressure deformable)
  • Deformable, processible as viscous melt
  • Hard at its use temperature
  • Liner chain structures
  • 2 kinds
  • Crystalline/sem-crystalline polymers (Tm)
  • Amorphous polymer (Tg) PS, PC, PMMA
  • Thermosetting (Heat cross-linked)
  • Sets cross-linked cured
  • Network or cross-linked architechure
  • Degrade rather than melt upon heating
  • Ealstomers crosslinked rubbery polymers
  • Stretchable, recoverable
  • Low cross-link density

21
Modulus vs Tg for thermoplastic polymers
22
Crystalline vs Amorphous
23
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24
Molecular Weight Distribution
25
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26
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27
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28
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29
Review Next Week
  • Table 1.1 and key properties
  • Polymer classification
  • Finalize top-10 list
  • Thermosetting vs thermoplastic polymers
  • 10/22 Wednesday RM210 Seminar
  • Stan Yang, Introduction of polymers for
    biomedical applications
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