Polymer Fundamentals

Question 1

What are polymers responsible for making?

Answer 1

*drugs
*suspending agents
*dressings
*tablets
*implants
*adhesives
*packaging
*film coatings

Question 2

What is a polymer?

Answer 2

• Polymers are a specific type of
  macromolecule – molecules composed of a
  large number of atoms with a high molecular weight
• Polymers are built up of repeating units called monomers

Question 3

What does the molecular weight of a polymer depend on?

Answer 3

The molecular weight of a
polymer varies and depends
upon the polymerisation
number (the lil n)

Question 4

What are the types of monomer arrangements?

Answer 4

• Monomers can be arranged in many different ways and there some common arrangements

*homopolymer
*Alternating copolymer
*Random copolymer
*Block copolymer
*Graft copolymer

(see pictures in folder)

Question 5

What does the properties of polymers depend on?

Answer 5

• The properties of polymers depend upon various factors:
  – Properties of the monomer itself, e.g. what functional groups are
  present?
  – Arrangement of the monomers (and the polymerisation number)
  – How the polymer chains interact with each other and/or the environment

Question 6

What are some properties of polymers?

Answer 6

*Block copolymers can act as emulsifying or
suspending agents

** Properties can change considerably with
crosslinking

Question 7

How are polymer properties vs small substances?

Answer 7

• Properties of polymers are very different
  from those of small (low MW) molecules
• Polymers exhibit more complex phase changes with
  temperature (there is no gaseous state)
• Dissolution of polymers is dependent upon numerous factors:
  – Polar / non-polar (the same as for small molecules)
  – Molecular weight
  – Prescence of crosslinking
  – Crystalline or amorphous form

*Low molecular weight
substances can typically
exist in three states with
clear boundaries
*Polymer solutions are
typically much more
viscous

Question 8

Polymers vs small molecules (molecular weight)?

Answer 8

• Small molecules have a fixed molecule
  weight whereas most polymers do not have
  an exact molecular weight  polydisperse
• Molecular weight quoted for a polymer is usually an average

Question 9

What does Mn and Mw stand for?

Answer 9

• Number average molecular weight (Mn)
• Weight average molecular weight (Mw)

Question 10

How do you calculate Mn?

Answer 10

(No. of moles × MW1) + (No. of moles × MW2) + .. MW 3 if there is one / total number of moles

Question 11

How do you calculate Mw?

Answer 11

(weight × MW1) + (weight × MW2) + …/ Total weight