Polymers

1
Polymers

• Polymers What are they?
• Different Types
• Uses and Applications
• Chemical Make-up

2
Polymers - What are they?

• Polymers are a special kind of macromolecule
• The word polymer comes from the Greek words
  poly, meaning many, and meres, meaning
  parts or repeating units
• A Polymer consists of a large chain of repeating
  molecules (monomers) that are attached in an end
  to end fashion

3
Description of Polymers

• Imagine a string of beads
• Each bead is identical (for example, red sphere)
• Represents the mer
• The string can contain 100s of beads
• Represents the poly characteristic
• The string in between the beads represents the
  chemical bond between monomers

4
Length of Polymers

• Polymer chains are HUGE!
• Polymers typically consist of between 20,000 and
  40,000 individual monomers
• If each bead on the string of beads were one inch
  apart, one polymer molecule could be as long as
  10 football fields!!!
• This chain length is what gives the polymer most
  of its desirable characteristics

5
Description of Polymers

• Polymer chains are flexible, and usually clump
  together into a smaller shape
• This enables the individual chains to interact
  and become entangled
• This helps to give a polymer its strength and
  flexibility

6
Types of Polymers

• There are two main types of polymers
• Natural
• (cotton, silk, wood, leather)
• Synthetic
• (plastics, nylon, latex)

7
Synthetic Polymers

• There are two basic types of synthetic polymers
• Thermoplastics (plastics, Styrofoam)
• These can be softened by heating and hardened by
  cooling - easily recycled
• Can easily be cast into various shapes
• Thermosets (epoxys, adhesives)
• These harden after being heated
• Can easily be cast into different shapes
• Cannot be reformed

8
Types of Polymers - Copolymers

• Most polymer chains are made up of one type of
  monomer (for example, red beads)
• However, some polymers are made up of different
  types of monomers (for example, blue and red
  beads) - these are called copolymers

9
Copolymers

• There are four main types of copolymers
• The different monomers can be arranged either in
  an alternating or random fashion
• Alternating
• ...-red-blue-red-blue-red-blue-red-blue-red-
• Random
• -blue-red-red-blue-red-blue-blue-red-blue-

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Copolymers

• There are also block copolymers and graft
  co-polymers
• Block
• -R-R-R-R-R-R-B-B-B-B-B-B-R-R-R-R-R-R-
• Graft
• -R-R-R-R-R-R-R-R-R-R-R-R-R-R-R-R-R-
• B-B-B-B-B-B-B-B-B-

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Polymers - Pros and Cons

• A polymer has many very advantageous properties.
  Polymers are
• Lightweight
• Strong and durable
• Cheap
• Easy to manufacture
• Unfortunately, polymers do not easily biodegrade
  and end up producing large amounts of waste

12
Uses of Polymers

• Polymers are incorporated into nearly every
  aspect of daily life
• Entertainment
• Sports
• Clothes
• Hobbies/Toys
• Household products
• Automotive

13
Polymer Chemistry

• A polymer chain is built on a Carbon backbone
• A monomer unit consists of a small carbon chain
  attached to a specific type of functional group
• The functional group is what gives each polymer
  chain its individual characteristics

14
Polymer Chemistry

• As previously stated, polymer chains interact
  with one another, becoming entangled
• Polymer chains also form cross-links with
  adjacent chains, which allows the polymer to hold
  its shape and gives added strength

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Summary

• Polymers are made up of large chains of repeating
  units, called monomers
• Individual chains interact to form a stronger
  overall substance through entanglements and
  cross-links
• Polymers are incorporated into almost every
  aspect of daily life
• Polymers are lightweight, strong, and inexpensive